Invoking Call with an invalid method will silently fail in C#

[andy-noisyduck]

Godot version:
3.2.3 (Mono)

OS/device including version:
Win 10

Issue description:
Any invocation of Call("method") to a method that does not exist will silently fail in C#. It will continue on as if the invocation was successful. This is obviously incorrect behaviour. The GDscript equivalent of the same code will correctly raise a "Nonexistent function" error.

Steps to reproduce:

// This will be silently ignored
Call("MethodThatDoesNotExist");

The equivalent GDScript code call("method_that_does_not_exist"); will correctly give the error `Invalid call. Nonexistent function 'method_that_does_not_exist (via call)'

Minimal reproduction project:
Testing-Call.zip
Repro project includes both C# and GDS versions of script.

[andy-noisyduck]

Not sure if #43282 (which seems to be specifically for Tool scripts) is also due to this bug.

[raulsntos]

• Sounds like a duplicate of [Mono] Node.Call() silently fails #59830.
• Should be fixed by C#: Print error when MethodBind/Callable call fails #79249 for 4.x. I understand you are unable to move to 4.x so I'll be keeping this issue open for 3.x.

[akien-mga]

Fixed by #79433.