Add patch-based test selection API endpoint

[suhaibmujahid]

Resolves #1718

Introduces a new /patch/<base_rev>/<patch_hash>/schedules endpoint to submit and retrieve test selection results for patches.

[Copilot]

Pull Request Overview

This PR adds a new API endpoint /patch/<base_rev>/<patch_hash>/schedules that enables test selection analysis for arbitrary patches. The implementation extracts common test selection logic into a reusable analyze_patch function and introduces functionality to parse patch files and generate minimal commit objects for analysis.

Key changes:

• Refactored schedule_tests to use a new shared analyze_patch function
• Added schedule_tests_from_patch function to handle patch-based test selection
• Implemented new REST endpoint supporting both GET and POST methods for patch submission and result retrieval

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
http_service/bugbug_http/models.py	Refactored test selection logic into analyze_patch, added schedule_tests_from_patch to process patches from Redis, and updated imports
http_service/bugbug_http/app.py	Added /patch/<base_rev>/<patch_hash>/schedules endpoint with GET/POST handlers, patch storage in Redis, and job scheduling

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[suhaibmujahid]

We are currently not pulling the repo, so base_rev is not used at the moment. If we end up with that, we should remove it before merging.