Wait for Web IDE commit animation

What does this MR do?

After clicking "Commit" there is an animation that hides that button and shows "Stage & Commit"

This change waits for the animation to complete before clicking "Stage & Commit" otherwise the click will quietly do nothing.

We also retry the attempt to click "Stage & Commit" just in case part of the animation is still in process even when the buttons have the expected visibility.

What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/55972

Does this MR meet the acceptance criteria?

• [-] Changelog entry added, if necessary
• [-] Documentation created/updated
• Tests added for this feature/bug
• [-] Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• [-] Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• [-] Security reports checked/validated by reviewer