Fix truncated messages for commits

What does this MR do and why?

Contributes to #357459 (closed)

Problem

Code responsible for displaying a list of last commits for each path truncates the commit message to 1Kb. But that leads to creation of the truncated markdown cache for commit description.

Solution

Trigger the markdown cache creation before the description is truncated.

Change of the flow:

Before	After
Fetch commits	Fetch commits
Convert commits to hashes	(NEW) Render description markdown for each commit (uses a non-truncated description)
Truncate commit messages	Truncate commit message
Save commits hashes in Redis	Save commits hashes in Redis
Restore commits from Redis	Restore commits from Redis
Render description markdown for each commit (BUG: uses a truncated a commit message)	Reuse the description markdown for each commit

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

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Before	After

How to set up and validate locally

1. Create or reuse an existing GitLab project
2. Clone the project locally
3. Add a new file
4. Add a very large commit message (example: jay_mccure/test_git_2@9b665bfe)
5. Push the change
6. Click on the commit
7. The commit message should not be truncated