feat(unlock-app): waits even in optimisitic checkout

[julien51]

Description

We are waiting for the tx to complete and updating the UX, even if the user is not required to wait and they can just close the modal.

Issues

Fixes ##13452
Refs #

Checklist:

• 1 PR, 1 purpose: my Pull Request applies to a single purpose
• I have commented my code, particularly in hard-to-understand areas
• I have updated the docs to reflect my changes if applicable
• I have added tests (and stories for frontend components) that prove my fix is effective or that my feature works
• I have performed a self-review of my own code
• If my code involves visual changes, I am adding applicable screenshots to this thread

Release Note Draft Snippet