[.NET] Allow forcing the enum suffix to avoid hiding members

[raulsntos]

What problem(s) does this PR solve?

A property and and enum can often have matching names after they are converted to PascalCase to follow C# naming conventions. When the property and the enum are declared in the same class this is not a problem because the bindings generator detects this and adds an Enum suffix to the enum type.

But when the property is declared in a derived class, it hides the enum type instead, which is now a CI error unless we explicitly suppress it, which we don't want to do often. This allows specifying which enums should always add the Enum suffix in the generated C# bindings, which solves these 2 issues:

• Can be used to prevent hiding members, resolving the CI error.
• Can also be used to avoid breaking compatibility later if a new member is added that matches the name of the enum, which seems to be the case in Add Trail3D class #117107.

Additional information

This can be used by #117107 to fix the current CI errors with a change like this:

diff --git a/modules/mono/editor/bindings_generator.cpp b/modules/mono/editor/bindings_generator.cpp
index 56c586752f3..3890c228cd6 100644
--- a/modules/mono/editor/bindings_generator.cpp
+++ b/modules/mono/editor/bindings_generator.cpp
@@ -153,7 +153,11 @@ const Vector<String> prop_allowed_inherited_member_hiding = {
 // This avoids hiding the enum when the property is declared in a derived class,
 // and the need for the 'new' keyword. It can also be used to avoid breaking compat
 // later if a new member is added with the same name as the enum.
-const Vector<String> enums_with_forced_suffix = {};
+const Vector<String> enums_with_forced_suffix = {
+	"Line3D.MaterialMode",
+	"Line3D.MeshAlignment",
+	"Line3D.TilingMode",
+};
 
 void BindingsGenerator::TypeInterface::postsetup_enum_type(BindingsGenerator::TypeInterface &r_enum_itype) {
 	// C interface for enums is the same as that of 'uint32_t'. Remember to apply

[paulloz]

Do we want to use this to limit current usages of new (e.g. all the occurrences of TextDirection)?

[raulsntos]

Changing TextDirection now would break compatibility. I think it would be a good idea to add the suffix for all new enums, but we'd need a way to know which version introduced the enum to avoid breaking compatibility for all existing enums, and that's not available in ClassDB.