Add run type legend tooltip to grid view

[pierrejeambrun]

Add an info icon next to the keyboard shortcut icon in the grid view that shows a tooltip with each DAG run type and its corresponding icon (Scheduled, Manual, Backfill, Asset Triggered).

Based on #61632, with review comments addressed.

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[pierrejeambrun]

Not sure why the original PR was closed, since this is a nice feature I created this PR as a followup.

[andreahlert]

Not sure why the original PR was closed, since this is a nice feature I created this PR as a followup.

Hey @pierrejeambrun don't worry. I'm not sure what happened to my #61632. I was reviewing multiple PRs, probably closed by accident. Good that you've got this.

[choo121600]

Cool, LGTM

[github-actions]

Backport failed to create: v3-1-test. View the failure log Run details

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
❌	v3-1-test

You can attempt to backport this manually by running:

cherry_picker 7f9ca03 v3-1-test

This should apply the commit to the v3-1-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

If you don't have cherry-picker installed, see the installation guide.