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: Avoid Corrupt Username (2)

Previous changes removed the ability to supply
control characters at the start and end of a
nickname; this change removes them from anywhere
in the nickname when supplied.

Change-Id: I0631fffa8aaf2c0e267c777892044c53faa4334e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7071
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

HaikuDepot: Avoid Corrupt Username

If the user happened to enter control characters into
their username when authenticating then the username
may cause problems later when communicating back to
the server. This is a hard problem to diagnose and
this commit will remove the problem.

Change-Id: Iad3c24f16cc6799ad8ddad634b8621a0aaadb921
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7067
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>