### Summary

Extend the template variable substitution to replace file paths. This
can be helpful for setting up log files & directories that should match
the repository name.

### PR Changes

 - Move files matching glob pattern when setting up repos from template
- For security, added ~escaping~ sanitization for cross-platform support
and to prevent directory traversal (thanks @silverwind for the
reference)
 - Added unit testing for escaping function 
- Fixed the integration tests for repo template generation by passing
the repo_template_id
- Updated the integration testfiles to add some variable substitution &
assert the outputs

I had to fix the existing repo template integration test and extend it
to add a check for variable substitutions.

Example:

![image](https://github.com/go-gitea/gitea/assets/12700993/621feb09-0ef3-460e-afa8-da74cd84fa4e)

Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

* Move some repository related code into sub package

* Move more repository functions out of models

* Fix lint

* Some performance optimization for webhooks and others

* some refactors

* Fix lint

* Fix

* Update modules/repository/delete.go

Co-authored-by: delvh <dev.lh@web.de>

* Fix test

* Merge

* Fix test

* Fix test

* Fix test

* Fix test

Co-authored-by: delvh <dev.lh@web.de>

* Start expansion

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* _template rather than .template

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Use ioutil

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Add descriptions to mapping

* Start globbing

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Tune globbing

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Re-arrange imports

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Don't expand git hooks

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Add glob tests for .giteatemplate

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Parse globs separately so they can be tested more easily

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Change template location and add docs

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* nit

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Update docs/content/doc/features/gitea-directory.md

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* Update docs/content/doc/features/gitea-directory.md

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* Add upper-lower case match

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Nits

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Update models/repo_generate.go

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>