Merge branch 'feat/issue-5700-dump-trace2-events-using-feature-flag' into 'master'

Create new hook to export git trace 2 events in gitaly logs

Closes #5700

See merge request !6570



Merged-by: Quang-Minh Nguyen <qmnguyen@gitlab.com>
Approved-by: Quang-Minh Nguyen <qmnguyen@gitlab.com>
Reviewed-by: Sami Hiltunen <shiltunen@gitlab.com>
Reviewed-by: Quang-Minh Nguyen <qmnguyen@gitlab.com>
Reviewed-by: Emily Chui <echui@gitlab.com>
Co-authored-by: Emily Chui <echui@gitlab.com>