Add unicode support for TH quotes (`[| |]`)
This has been mentioned before but didn't have it's own ticket.
The following where mentioned in #2978 (closed), but the respective patch did not include them:
- For TemplateHaskell:
⟦ ⟧
(MATHEMATICAL _ WHITE SQUARE BRACKET) can be used instead of[| |]
- For Generics:
⦃ ⦄
(_ WHITE CURLY BRACKET) can be used instead of{| |}
- For Arrows:
⦇ ⦈
(Z NOTATION _ IMAGE BRACKET) can be used instead of(| |)
Generic classes have since been removed and banana brackets were suggested in #10162 (closed) and implemented in D2012, leaving TH quotes.