Add initial x509 tool

[ecdeye]

Description:

• Developed structure for new OpenSSL tools
• Contains initial implementation for OpenSSL x509 tool, options -in and -out (x509.cc), and unit test (x509_test.cc)
• x509_test.cc contains test portions ultimately to be used for future options but unnecessary for -in/-out unit test

Files expected to change

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 59.45946% with 30 lines in your changes missing coverage. Please review.

Project coverage is 78.19%. Comparing base (21c5e48) to head (af1d491).

Files	Patch %	Lines
tool-openssl/x509.cc	48.78%	21 Missing :warning:
tool-openssl/x509_test.cc	72.72%	5 Missing and 4 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1666 +/- ## ========================================== - Coverage 78.26% 78.19% -0.07% ========================================== Files 567 571 +4 Lines 95238 95400 +162 Branches 13673 13704 +31 ========================================== + Hits 74535 74600 +65 - Misses 20109 20189 +80 - Partials 594 611 +17 ```

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