[WIP] PoC: Offline editing

[miina]

Description

This is a PoC PR with the goal of:

• Allow editing a previously loaded post only.
• Display a message about being offline and let the user know that it will be updated later.
• First step: ignore changes done by anyone else and always update the post content when online again.

Potentially later:

• Second step: Use If-Unmodified-Since and create a revision only if the post has been modified meanwhile.

How has this been tested?

Screenshots

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR. .

[miina]

This should check that it's actually for editing the post

[westonruter]

Does the index.php here imply that pretty permalinks are not enabled?

[miina]

Yes, that's currently the case.