feat: improve `BlockToolAdapter`

[himself65]

Checklist

• [x] Native inputs handling

• Input element

• Textarea element

• Handle non-text input elements

• [x] Contenteditable element handling

• [x] improve playground

• supported backspace and delete for native inputs Left todo for native inputs (support all deletion cases manually)

[gohabereg]

for html textarea, should we create a new paragraph or something when user press Enter?

No, we'd like to preserve browser behaviour there. If some other behaviour is desired by a tool it should be implemented by the tool

[himself65]

We'd like to preserve browser behavior there.

Is it a good idea that keep the default behavior?

Benefit is we don't need to handle all cases for cross-browser manually, but I think there would be some issue when bringing the collaborative feature in

Never mind, bad idea