Unit tests for SRT socket options API

[maxsharabayko]

This PR contains:

1. Unit tests (test_socket_options.cpp):

   • Min values
   • Max values
   • Default values
   • Invalid values
   • Restrictions: after bind, after connection.

2. Some fixes for socket options API (to be merged separately)

Derived PRs: #1921, #1922, #1925, #1931, #1939, #1940, #1941, #1948, #1954, #1956.

TODO

• Revealed unprotected access to CUDT::m_Status. See docs/Synchronisation.md. Create an issue?
• Fix SRTO_TLPKTDROP: get config value until connected. Conflicts with bool type fixe in Fixing srt_getsockopt for bool socket options #1925.

[maxsharabayko]

TODO:

• PR Cleanup CSrtConfigSetter #2053 touched socket config. Finish up the work on this PR.