Enable Blame page pagination by default

What does this MR do and why?

Contributes to #360927 (closed)

Enable pagination support for file blame with more than 1000 lines

Screenshots or screen recordings

How to set up and validate locally

1. Enable feature flag

   Feature.enable(:blame_page_pagination)

2. Visit http://127.0.0.1:3000/gitlab-org/gitlab-test/-/blame/master/files/markdown/ruby-style-guide.md

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.