Crate kind_pass

A lot of transformations that we can apply into kind trees.

• desugar - That desugars the sugared tree into a version that does not contain a lot of constructions like match, inductive types etc.
• erasure - Erases all of the definitions that are marked as erased from the runtime.
• expand - Expand some attributes and derivations of each construction.
• unbound - Collects all of the unbound definitions and check the linearity of them.
• inline - Inlines expressions

Modules

• desugar
  This pass transforms a sugared tree into a simpler tree.
• erasure
• expand
  Expand some attributes and derivations of each construction. Currently it just derives match and open for sum type and record types respectively.
• inline
• subst
• unbound
  Collects all the unbound variables, check if patterns are linear and check if the name belongs to the current module.