- Added and corrected JavaDocs.
- Deprecated unused public methods.
- Fixed first tab style logic in TabSheet.
- Fixed navigation focus logic in TabSheet.
- Fixed tab width bookkeeping for scrolling TabSheet tabs.
- Renamed private methods and variables for clarity.
- Removed unnecessary or duplicated private methods.
- Reworked some logic to clarify it and to better match my understanding
of what's supposed to happen within those methods.
- Updated some deprecated method calls to use currently recommended
solutions.
- Added and updated regression tests.

On HCL Digital Experience 8.5.5 CF19, the `getPortalInfo()` method returns
"hcl digital experience/8.5", breaking detection of the servlet engine.

This ultimately leads to methods such as `getHeader()` to return NULL, as
the upstream HTTP request is not retrieved.

Moving to new version removes the warning
com.vaadin.event.EventRouter addListener WARNING: Adding listeners with type Object is deprecated, event listener should extend SerializableEventListener

It is possible findOrCreateVaadinSession leaves session locked if HTTP session is invalidated in an another thread between lockSession and unlockSession calls. This PR changes the implementation so that this can no longer happen.

fixes: #12352

This is both a optimization by skipping duplicate validation round and avoids ConcurrentModificationExpectation being thrown certain corner cases.

- Added and completed JavaDocs.
- Fixed a typo in logging.
- Removed an unused parameter in a private method.

Also added missing JavaDocs.

- Added, completed, and corrected JavaDocs.
- Added an assert to enforce a condition that has always been required.
- Added default sections to switch blocks.
- Added wildcards.
- Deprecated unused methods and variables.
- Removed inner assignments.
- Removed unused private variables and calls that do nothing.
- Updated deprecated calls to use currently recommended versions.
- Updated warning suppressions.
- ...and some auto-formatting.

Bumps [jetty-webapp](https://github.com/eclipse/jetty.project) from 9.4.41.v20210516 to 9.4.43.v20210629.
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](https://github.com/eclipse/jetty.project/compare/jetty-9.4.41.v20210516...jetty-9.4.43.v20210629)

---
updated-dependencies:
- dependency-name: org.eclipse.jetty:jetty-webapp
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Modified cherry-pick of https://github.com/vaadin/flow/pull/11428

Fixes #12341

- Added missing default sections to switch blocks.
- Added missing JavaDocs and JavaDoc parameters.
- Added wildcards where possible.
- Deprecated unused method.
- Fixed JavaDoc formatting.
- Removed inner assignments.
- Removed unused imports.
- Removed unused variables.
- Removed warning suppressions that were unnecessary or about boxing
(not tracked by coding conventions).
- Suppressed warnings about rawtypes, deprecation, and unchecked where
couldn't be avoided.

- removed unused private methods
- removed unused private variables
- removed unnecessary initializations
- removed unnecessary substring(0)
- removed inner assignments
- renamed private methods that started with upper case
- renamed static final variables to use upper case
- converted to use non-deprecated options
- suppressed unavoidable warnings
- divided long Strings to multiple lines
- added missing types
- added missing JavaDoc parameters
- formatting
- updated comments & JavaDocs

Fixes: #12328

Also prevents opening FileSystem for unknown schemes.

Modified cherry-picks of https://github.com/vaadin/flow/pull/11072 ,
https://github.com/vaadin/flow/pull/11147 , and
https://github.com/vaadin/flow/pull/11235

* fix: add JavaDoc warning to avoid using ResponseWriter for directories

Cherry-picked from: https://github.com/vaadin/flow/pull/11112

- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](https://github.com/eclipse/jetty.project/compare/jetty-9.4.38.v20210224...jetty-9.4.41.v20210516)

---
updated-dependencies:
- dependency-name: org.eclipse.jetty:jetty-servlets
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

* Small updates to servlet container test setup.

- Upgraded to use cargo-maven3-plugin since cargo-maven2-plugin is now
EOL.
- Defined supported packagings as the current jetty-maven-plugin default
only covers war.
- Changed a test pojo to implement Serializable in order to prevent an
error in cargo-maven3-plugin stop-container phase.

Fixes #12310

Fixes concurrency issue with UUIDBroadcasterCache that may lead to loss of packets and thus repeated resynchronizations when using Push.

* Updated comparison screenshots for servlet containers module.

- Backspace navigation hasn't worked in years thanks to new browser
standards, removed related tests. Left a test for regular backspace use
within a modal window.
- Enabled a modal window test for Chrome since it seems to be working
now, removed extending of another test class to avoid running the tests
twice without any configuration changes.
- Adjusted browser width limitation.
- Added screenshots.

Fixes: https://github.com/vaadin/framework/issues/12285

* Test screenshots for Firefox

Bumps commons-io from 2.4 to 2.7.

Signed-off-by: dependabot[bot] <support@github.com>

* Attempts to reduce test flakiness

Fixes #10435

Handle possible race condition by disabling the editor's widget while awaiting validation from the server.

Fixes #12270

* Add browser specific handling in setRows

Fixes: https://github.com/vaadin/framework/issues/10138

Fixes: https://github.com/vaadin/framework/issues/7878

* Enforced minimum height to 1 rows and added a test.

Co-authored-by: Anna Koskinen <anna@vaadin.com>

- Added check for touch move event in order to allow the same flow for
both mouse and touch events when dragging a Window by its header.
- Can be tested with SubwindowDraggability class.

Fixes #12257

Co-authored-by: Jakub Antoniak <j.antoniak8@gmail.com>

* Add ErrorHandler to AbstractTestUI

This reverts commit 8c39731123.

Avoids dependency security alert

- Override ParallelRunner of TestBench 5.2.0 for uitest module in order
to intercept and log uncaught exceptions in
TBMethod.invokeExplosively(...).