Displays loading icon in async buttons inline

What does this MR do?

Displays loading icon inline instead of in a new line

Does this MR meet the acceptance criteria?

• Tests
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #32954 (closed)

@iamphill can you please review this one? Thanks!

assigned to @iamphill

approved this merge request

merged

mentioned in commit 77ba9a54

mentioned in issue #33450 (closed)

Picked into 9-2-stable; will go into v9.2.6.

/cc @selfup @ClemMakesApps @kushalpandya

mentioned in commit 3c42294b