Vscode: Support embedded modes for TextMate grammars

[aeschli]

With TextMate grammars we no longer support embedded modes which control the behaviour of smart editing (brackets, comments).

Text mate scopes can be used for that, but we should fix the flattening of scopes first (#3008)

[alexdima]

IMHO each and every one of the linked issues needs to be verified independently, as the generation of mode transitions from TM tokens depends heavily on the TM grammar (i.e. if the grammar does not use top-level scope names in the embedded portions, the mode transitions auto-generation will not work).

It works however for HTML, which uses source.css.embedded.html for embedded css, etc.

The relevant plan item is #14136

[chjtx]

I hate TextMate, and how can I remove it?

[wxs77577]

still not work, how to fix?