lang: Number in method name causes incorrect serialization

[armaniferrante]

my_method_2 doesn't serialize properly when testing with javascript. This is likely because the IDL's conversion to camelCase makes it ambiguous as to whether the name is my_method2 vs my_method_2. Fix should be to use snake_case in the IDL.

[paul-schaaf]

@armaniferrante just to make sure I understand correctly, are you saying that the IDL and therefore the clients should just use snake_case and we remove the conversion to camelCase? So the js function will look exactly like the anchor rust function?

[armaniferrante]

This is addressed by #912.

[acheroncrypto]

Fixed in #2824.