add cirru-quote variant for better meta programming

[tiye]

Since Cirru is a syntax for various DSLs, there are many cases we want to embed Cirru inside Calcit code to program other DSLs. To make it convenient and more performance, CirruQuote variant is added into core.

New APIs:

• cirru-quote which is a special form are symbol reading phase,
• parse-cirru-list, which is previously parse-cirru that returns list, so it's breaking change,
• parse-cirru, which returns CalcitCirruQuote variant.
• &cirru-quote:to-list, which converts CalcitCirruQuote into Calcit list.

This is designed to simplify calcit-calx and calcit-wasmtime, and will probably break docs site.

[tiye]

also noticed, cirru-quote takes effect at reader phase, which means before quote takes effect:

=>> cr -e 'println $ quote $ cirru-quote 1'
(&cirru-quote 1)

which makes it tricky to create quoted data that contains cirru-quote:

=>> cr -e 'println $ quasiquote $ a (~ (turn-symbol "|cirru-quote")) b'
([] 'a 'cirru-quote 'b)

and quote inside Cirru EDN is a different story.