text input: Disable erasing
Erasing with zwp_text_input_v3 version 1 requires bytes, and bytes require get_surrounding_text. That, however, is optional. That's a mistake in protocol design.
Easiest to drop this until the mess is solved on the protocol side.
@sebastian.krzyszkowiak could you make sure I didn't make a mistake with condemning the protocol before I go all out to fix it?