HaikuDepot : Improve Language Code Handling

HDS is soon going to be enhanced to deal with more than
just the two-character ISO language codes that it
currently supports. The logic in HD is currently expecting
that HDS will only supply these two character codes. This
change is about making adjustments to be able to cater to
any ICU language IDs from HDS.

The naming in HDS is still going to continue to use the
terminology that it currently does; it will call the
identifier for a language a "natural language code". The
HD source will instead reflect the nomenclature of ICU
and call the same thing a language ID.

Change-Id: Ib138c2e3b7b667edf15cd497c2f710f80b3c29f8
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7424
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Niels Sascha Reedijk <niels.reedijk@gmail.com>

HaikuDepot: Password Requirements

Obtains HDS's password requirements and displays
those to the user when creating a new account.

Relates to #13986

Change-Id: I1b76181e17bc03e9baf915dadcd3c45f9eb89b3f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6203
Tested-by: Automation <automation@haiku-os.org>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

HaikuDepot: Refactor of Login

These changes cover a rework of the login and
account creation logic before making additional
changes related to the user usage conditions.

Relates to #15209

Change-Id: I90b7dbcee5b0285476938c6ced0afc89483d6227
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2023
Reviewed-by: Stephan Aßmus <superstippi@gmx.de>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

HaikuDepot: Conditions on Create User

When the user chooses to create a new user they
are able to view the current usage conditions for
users. They are also required to agree to the
conditions and they are required to confirm that
they meet the minimum age requirement.

Relates to 15209

Change-Id: I83cdaabe1b3da31a4cd21139b72341f4b93cab85
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1842
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

HaikuDepot: Load Languages from HDS

The HaikuDepot application has, thus far had its
own hard-coded list of languages that the user is
able to choose when (a) creating a new account or
(b) creating a user-rating. This change will mean
that those languages are loaded from the HDS
server dynamically and in this way the user can
choose from the full list. There have also been
improvements to the way in which the languages are
displayed in the menu as well.

Change-Id: If7cb7b87f348ca59d503d276a22444e72d0e6168
Reviewed-on: https://review.haiku-os.org/c/1425
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

HaikuDepot: Validate input before creating account

Provide error or info alert when fields are invalid, suggest
providing an email, but allow to ignore the warning.

HaikuDepot: Request to login before rating a package

* There is now a flow of logging in or creating an account before being
able to rate a package and the user is not yet logged in. The
UserLoginWindow stores an "on success" BMessenger and BMessage which are
send after the alert which confirms successful login or account creation.
This is used to make the RatePackageWindow show once logged in successfully.

HaikuDepot: Limit language selection for account creation

For the time being, there is a limited amount of supported languages
when creating accounts, reflect this in the UI and use a BMenuField.
Creating accounts with other languages fails, the error reporting was
not ideal and could be improved. The server responded with "object not found",
which was reported in the alert, but the response actually contains the
object which was not found (NaturalLanguageCode).

HaikuDepot: Organized source into sub-folders

HaikuDepot: Validate input before creating account

Provide error or info alert when fields are invalid, suggest
providing an email, but allow to ignore the warning.

HaikuDepot: Request to login before rating a package

* There is now a flow of logging in or creating an account before being
able to rate a package and the user is not yet logged in. The
UserLoginWindow stores an "on success" BMessenger and BMessage which are
send after the alert which confirms successful login or account creation.
This is used to make the RatePackageWindow show once logged in successfully.

HaikuDepot: Limit language selection for account creation

For the time being, there is a limited amount of supported languages
when creating accounts, reflect this in the UI and use a BMenuField.
Creating accounts with other languages fails, the error reporting was
not ideal and could be improved. The server responded with "object not found",
which was reported in the alert, but the response actually contains the
object which was not found (NaturalLanguageCode).

HaikuDepot: Organized source into sub-folders