[Javascript] String interpolation uses odd scope names

[FichteFoll]

Continued from #141.

Currently, string interpolation in the form let str = I'm a ${"string"}.; has the following issues:

1. the meta name is string.quasi. I think this should be string.interpolated.backtick
2. backtick punctuation gets the scope names punctuation.definition.quasi.begin. Imo it should be punctuation.definition.string.begin.interpolated (and end respectively)
3. the pattern denotation is marked as punctuation.quasi.element.begin. I suggest punctuation.definition.begin.section.interpolated or similar.
4. the entire pattern is scoped as entity.quasi.element. Entitiy is definitely wrong here. I'm unsure atm what should be used instead (maybe keyword), but something with embedded would be a good start.

[FichteFoll]

Closed in favor of #165.