Support .git-blame-ignore-revs file (#26395)

Closes #26329

This PR adds the ability to ignore revisions specified in the
`.git-blame-ignore-revs` file in the root of the repository.


![grafik](9e91be0c-6e9c-431c-bbe9-5f80154251c8)

The banner is displayed in this case. I intentionally did not add a UI
way to bypass the ignore file (same behaviour as Github) but you can add
`?bypass-blame-ignore=true` to the url manually.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/tests/repos/repo6_blame/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/master

modules/git/tests/repos/repo6_blame/config

@@ -0,0 +1,4 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = true

modules/git/tests/repos/repo6_blame/refs/heads/master

@@ -0,0 +1 @@
+544d8f7a3b15927cddf2299b4b562d6ebd71b6a7