Add information to `callstack` if error object exists

[zero-plusplus]

RELATED: #223

The following implementation methods are being considered.

• Treat a specific name (e, err, error, etc.) as an error object and add it to the call stack after checking
• Search variable list and add matching error object to call stack

[zero-plusplus]

I am putting this issue on hold because implementing a reliable way to get the error object passed to the catch statement is a bit of a challenge without a parser.

I plan to implement this after the parser under development is completed.

[zero-plusplus]

AutoHotkey v1.1.36 adds exception breakpoint and a special variable <exception> that refers to error objects.

Therefore, I close this issue once.