add AST builder procs

[haxscramper]

initial collection of the procedure to see whether the idea is useful enough to extend it further.

per earlier discussion in matrix, @saem

yeah, this is closer, I think the API should feel a bit like you're writing jsx in react. You simply write the tree as it should be produced, in a single expression. Breaking it up would mean function call in the expression but otherwise just "draw" it like it should be.

[haxscramper]

I temporarily converted this into a draft PR, I will return to it later on when I have more time to (approximately July 22nd or later)