rename and move some files
add `Bool for ast
advantage:
more precise semantics: like [is_irrefutable_pattern]
adapt parser except lexer now..
switch to `Bool succeed -- now to turn off the keyword convention
get rid of ast node like Lid "true",
probably we need a safety check when dumping Lid --> to Parsetree, this is necessary considering we allow anti quotation --
`Uid "()" -- deprecated
use `Unit instead
sanitize check needed later
todo: fix toplevel bug