Support AWS-LC in FIPS mode

[mulmarta]

Changes:

• FIPS does not have X509_get0_pubkey so it's replaced by X509_get_pubkey which differs in requiring free of the key
• It seems that aws-lc-rs updated BIO_number_written and now it returns u64 instead of usize. This is not the case for FIPS.

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

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 88.23529% with 4 lines in your changes missing coverage. Please review.

Project coverage is 90.16%. Comparing base (c710afa) to head (ffff30b).

Files with missing lines	Patch %	Lines
mls-rs-crypto-awslc/src/x509/component.rs	50.00%	3 Missing :warning:
mls-rs-crypto-awslc/src/x509/certificate.rs	96.15%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #198 +/- ## ========================================== + Coverage 90.15% 90.16% +0.01% ========================================== Files 175 175 Lines 31396 31408 +12 ========================================== + Hits 28306 28320 +14 + Misses 3090 3088 -2 ```

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