* [REF-2787] add_hooks supports Var-wrapped hooks
* Fix VarData definition in .pyi file to allow removal of type ignore comments
* Var.create and Var.create_safe accept _var_data parameter
* Replace instances where a set of imports was being passed to VarData
* Update code throughout reduce use of `._replace` to add VarData
* Fixup: user hooks _var_data.imports will never be iterable, just a single ImportDict