List, indent and indent list tab accessiblity improvements

[12joan]

Description

The list, indent and indent list plugins should be judicious about when they override the default tab key behaviour.

Expected Behavior

At minimum, the following rules should be added:

• If tab or shift+tab doesn't result in a transform, the default browser behaviour should be used
• If the selection is expanded and confined to a single block (e.g. a single word is selected), tab and shift+tab should use their default browser behaviour
  • This is intended to ensure that keyboard users can access the formatting toolbar to add or remove formatting for selected words inside lists or other indentable blocks.

Bounty

Click here to add a bounty via Algora.

Funding

• You can sponsor this specific effort via a Polar.sh pledge below
• We receive the pledge once the issue is completed & verified