remove some underscores

[JeffBezanson]

Part of #20402.

• deprecate catch_stacktrace
• rename method_exists to hasmethod
• rename object_id to objectid

[ararslan]

Nice, thanks! I especially like hasmethod.

[nalimilan]

+1 in general, but I'm not sure I like hasmethod: who's the subject of "has", given that there are multiple types?

[JeffBezanson]

The function has the method.

[vtjnash]

The function has the method.

Actually, I agree this is a bit weird. Functions don't have methods. The global MethodTables has methods, with symmetric dispatch across all arguments (including the first argument, which in many cases is a Function).

[JeffBezanson]

In generic function systems, functions are traditionally considered sets of methods. True, that's not exactly how it works in julia, but the query hasmethod(f, types) is formulated in those terms.

We could also have a 1-argument version, e.g. hasmethod(Tuple{ftype, argtype}) and I think it might still make sense; you're asking if the system has such a method.