modelbuilder: `resolve_mtype` require a MClassDef instead of a AClassdef

This also simplify some the clients.

Signed-off-by: Jean Privat <jean@pryen.org>
modelize_property: remove usage of `nclassdef`

nclassdef are less needed, so just not use them when possible.

Signed-off-by: Jean Privat <jean@pryen.org>
typing: TypeVisitor need mmodule and mpropdef, not aclassdef

This will help to analyze code with a injected context

Signed-off-by: Jean Privat <jean@pryen.org>
modelbuilder: considers that mentities outside the modelbuilder are safe

When playing with injected code, a specific modelbuilder should only bother
to recursively build its knowledge

Signed-off-by: Jean Privat <jean@pryen.org>