ci: Improve test failure automated issues

What does this MR do and why?

Improvements after initial implementation in !104983 (merged).

This changes a few things to failing test automated issues:

• Change the failing test issues title to include [test-hash:...] instead of - ID: ..., to hopefully clarifies that the hash is a hash of the test filename+title, not a commit hash
• Adds a link on the test file path
• Add the number of reports to the ### Reports header
• Change the report list to be numbered
• Adds the current date to new report lines
• Set the issue weight with the number of reports

Example of an old-formatted issue update: https://gitlab.com/gitlab-org/quality/engineering-productivity/flaky-tests-playground/-/issues/337#note_1324256359

Screenshots or screen recordings

New issue format

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.