Refactor TLS 1.3 cipher selection and fix SSL_get_ciphers

[smittals2]

Issues:

CryptoAlg-2559

Description of changes:

1. SSL_CTX_new now configures ctx->tls13_cipher_suites with default TLS 1.3 ciphers (did not previously). The default preference order for TLS 1.3 ciphersuites differs based on whether AES Hardware acceleration is enabled in AWS-LC, we match this behavior in SSL_CTX_new.
2. The SSL_CONFIG object holds it's own TLS 1.3 ciphersuites now
3. Server side and client side cipher selection logic is modified to account for the new field in SSL_CONFIG
4. Each time a cipher list is configured either on SSL_CTX or SSL_CONFIG, the main cipher_list is updated with values from its own tls13_cipher_suites via a new function update_cipher_list. This function also updates in_group_flags accordingly. This means, TLS 1.3 ciphersuites are stored seperately while the main cipher_list var holds ALL ciphersuites in both objects
5. Outdated comments were updated

Call-outs:

Note SSL_CTX generally has a longer lifetime than an SSL object. SSL_CONFIG objects live on SSL objects. Both SSL_CTX and SSL_CONFIG have their own cipher_list and tls13_cipher_list fields. We support SSL_[CTX]_set_... APIs to set these fields.

In general, our TLS implementations pick cipher suites against the given connection constraints/parameters. Adding TLS 1.3 ciphersuites to ctx->cipher_list or config->cipher_list does not modify this behavior or introduce new problems.

Testing:

Added new testing to validate cipher selection behavior between SSL_CTX and SSL_CONFIG objects
Added change detection test for TLS 1.3 Client Hello
Updated old tests and to-do's regarding TLS 1.3
Testing to ensure SSL_get_ciphers returns ALL ciphersuites instead of TLS 1.2 and below.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 93.33333% with 9 lines in your changes missing coverage. Please review.

Project coverage is 78.99%. Comparing base (695c3a0) to head (cc21d89).

Files with missing lines	Patch %	Lines
ssl/ssl_cipher.cc	88.09%	5 Missing ⚠️
ssl/ssl_lib.cc	93.93%	2 Missing ⚠️
ssl/ssl_test.cc	95.91%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2092      +/-   ##
==========================================
+ Coverage   78.96%   78.99%   +0.02%     
==========================================
  Files         611      611              
  Lines      105514   105603      +89     
  Branches    14941    14958      +17     
==========================================
+ Hits        83319    83420     +101     
+ Misses      21543    21531      -12     
  Partials      652      652              

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