This makes sure that assigning values to enum-typed variables are
consistent. Same enum is always valid, different enum is always
invalid (without casting) and assigning `int` creates a warning
if there is no casting.
There are new test cases to ensure this behavior doesn't break in
the future.
Inline getters & setters are now FunctionNodes.
Their names are set in the parser, not in the compiler.
GDScript-Analyzer will now run through getter and setter.
Also report wrong type or signature errors regarding getset properties.
Added GDScript tests for getters and setters.
#53102
