feat(pytest): add pytest-html plugin for html reports

[danceratopz]

🗒️ Description

• Adds the pytest-html plugin to EEST's dependencies so that html test reports can be generated for fill executions.
• Generates html report by default. Default location is the root of fill's output directory (--output, default is ./fixtures).
• Adds fill command-line options and t8n/solc versions to the report Environment section.
• Adds links to the JSON fixture and --evm-dump-dir for each test (see screengrab).

Demo screengrab of report below.

TODO

• 1. Add relevant config/metadata (solc version, t8n version) to "Environment" Table (see screenshot).
• 2. Enable by default and write to fixture output directory (we could use click to specify output directory, but perhaps the plugin has an option to help manage this).
• 3.a. Add new "Test fixture" column to the "Summary" table (or in "Links" column?). Add link to the locally generated json fixture, if test is pass.
• 3.b. Add new "Debug output dir" column to the "Summary" table with link (or in "Links" column?), if option is enabled.

Other tasks beyond the scope of this PR:

• 4. Enable for framework tests?
• 5. Use in CI/CD?

Considerations for use in CI/CD:

• Filling with Cancun generates an html report of 5.9 M, even if all tests pass.
• There seems to be negligible impact on runtimes with reporting enabled.

HTML Report Features Demo

🔗 Related Issues

None

✅ Checklist

• All: Set appropriate labels for the changes.
• All: Considered squashing commits to improve commit history.
• All: Added an entry to CHANGELOG.md.
• All: Considered updating the online docs in the ./docs/ directory.
• Tests: All converted JSON/YML tests from ethereum/tests have been added to converted-ethereum-tests.txt.
• Tests: Included the type and version of evm t8n tool used to locally execute test cases: e.g., ref with commit hash or geth 1.13.1-stable-3f40e65.
• Tests: Ran mkdocs serve locally and verified the auto-generated docs for new tests in the Test Case Reference are correctly formatted.

[marioevz]

Very nice! thanks!