Follow  #30472:

When a user is created by command line `./gitea admin user create`:

Old behavior before #30472: the first user (admin or non-admin) doesn't
need to change password.

Revert to the old behavior before #30472

Unify the behaviors of "user create" and "user change-password".

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

Fixes #28660
Fixes an admin api bug related to `user.LoginSource`
Fixed `/user/emails` response not identical to GitHub api

This PR unifies the user update methods. The goal is to keep the logic
only at one place (having audit logs in mind). For example, do the
password checks only in one method not everywhere a password is updated.

After that PR is merged, the user creation should be next.

This PR adds a new `must-change-password` parameter to the
`change-password` cli command.
We already have the `must-change-password` command but it feels natural
to have this integrated into the `change-password` cli command.

---------

Co-authored-by: 6543 <6543@obermui.de>

Replace #10912

And there are many new tests to cover the CLI behavior

There were some concerns about the "option order in hook scripts"
(https://github.com/go-gitea/gitea/pull/10912#issuecomment-1137543314),
it's not a problem now. Because the hook script uses `/gitea hook
--config=/app.ini pre-receive` format. The "config" is a global option,
it can appear anywhere.

----

## ⚠️ BREAKING ⚠️

This PR does it best to avoid breaking anything. The major changes are:

* `gitea` itself won't accept web's options: `--install-port` / `--pid`
/ `--port` / `--quiet` / `--verbose` .... They are `web` sub-command's
options.
    * Use `./gitea web --pid ....` instead
* `./gitea` can still run the `web` sub-command as shorthand, with
default options
* The sub-command's options must follow the sub-command
* Before: `./gitea --sub-opt subcmd` might equal to `./gitea subcmd
--sub-opt` (well, might not ...)
    * After: only `./gitea subcmd --sub-opt` could be used
    * The global options like `--config` are not affected

This PR refactors and improves the password hashing code within gitea
and makes it possible for server administrators to set the password
hashing parameters

In addition it takes the opportunity to adjust the settings for `pbkdf2`
in order to make the hashing a little stronger.

The majority of this work was inspired by PR #14751 and I would like to
thank @boppy for their work on this.

Thanks to @gusted for the suggestion to adjust the `pbkdf2` hashing
parameters.

Close #14751

---------

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

As part of administration sometimes it is appropriate to forcibly tell
users to update their passwords.

This PR creates a new command `gitea admin user must-change-password`
which will set the `MustChangePassword` flag on the provided users.

Signed-off-by: Andrew Thornton <art27@cantab.net>