add conn_max_idle_time and pool_timeout to Finch

[wawashra]

Description

Fixes:

Type of change

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• Performance boost or paying a technical debit 💰 (non-breaking change).
• This change requires a documentation update.

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Manually tested (Self-tested).
• With the help of our Quality Assurance people.
• Added automated tests for it 🥇.

Checklist:

• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• Any dependent changes have been merged and published in downstream modules.
• I have checked my code and corrected any misspellings.

[amazon-inspector-oregon]

⏳ I'm reviewing this pull request for security vulnerabilities and code quality issues. I'll provide an update when I'm done

[amazon-inspector-oregon]

✅ I finished the code review, and didn't find any security or code quality issues.