[Feature]: Configurable tab to space conversion
### What's the feature?

tldraw currently seems to convert typed/pasted tabs to 2 spaces. Could this behaviour be made configurable using preferences to specify:
- Whether tabs get converted to spaces at all (`true` by default).
- The indent width (`2` by default) according to which tabs are rendered or converted to spaces.

This way,
- Conversion can be switched off to preserve the indentation of typed/pasted text. _I'd have it switched off because I paste blocks of tab-indented code into tldraw to copy out later, and I'd prefer not to have to fix the indentation when doing so._
  - My understanding is that tab indentation could cause export bugs (#1387) so if this feature would cause them to resurface, the export could always convert tabs to spaces using the indent width preference regardless of the conversion preference where necessary.

- If conversion is switched on, tldraw could convert tabs to spaces according to the indent width. _I'd have this set to 4 because I find larger snippets easier to read when they're 4-indented instead of 2-indented._

- If the preferences could be associated with the project (`.tldr` file?) or page, one wouldn't have to reset them whenever they switch between those contexts.

Thoughts 😊?

### Where would you like this feature?

The tldraw.com website

### Contact Details

_No response_

### Code of Conduct

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