Refactor e2e-tests.yml workflow

[cmurphy]

• Rewrite the shell scripts run in e2e-secrets and e2e-tsa-mtls as Go tests.
  • Since these tests were being run on macos and ubuntu runners, we still keep them separate from the regular e2e tests to maintain platform testing parity.
  • They can be combined into a single job.
  • e2e-test-pkcs11 is left alone, since it is already running Go tests and the script is necessary to set up the pkcs11 docker container.
• Reorganize e2e_test.go so that tests that are related to attachment are part of the e2e_attach_test.go file. This makes e2e_test.go a little smaller and makes it possible to run these tests on the macos runner.
• Remove all the now-unused hardcoded key files and the key generation scripts.

  Release Note

  Documentation

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 39.94%. Comparing base (2ef6022) to head (2f674bb). Report is 60 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #3627 +/- ## ========================================== - Coverage 40.10% 39.94% -0.17% ========================================== Files 155 155 Lines 10044 10087 +43 ========================================== + Hits 4028 4029 +1 - Misses 5530 5584 +54 + Partials 486 474 -12 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[haydentherapper]

Can we add a README in the test directory summarizing these different test files, to help direct implementers to where they should add tests, and discourage shell script tests?

[haydentherapper]

Merging since none of the comments are blocking and since any open PRs might need to redo tests. Thanks again!