Add changelogs

changelogs/unreleased/49854-recover-mr-regression-fixes-safe-1.yml

+---
+title: Fix rendering of the context lines in MR diffs page.
+merge_request: 20968
+author:
+type: fixed

changelogs/unreleased/49854-recover-mr-regression-fixes-safe-2.yml

+---
+title: Fix autosave and ESC confirmation issues for MR discussions.
+merge_request: 20968
+author:
+type: fixed

changelogs/unreleased/49854-recover-mr-regression-fixes-safe-3.yml

+---
+title: Fix navigation to First and Next discussion on MR Changes tab.
+merge_request: 20968
+author:
+type: fixed