Fix multi-argument gesture dispatcher parsing

[kolayne]

Describe your PR, what does it fix/add?

The dispatcher gesture handler used to only handle
the first argument to the dispatcher, while some dispatchers
(e.g., sendshortcut) want multiple arguments.

This fixes ConfigManager to handle all the arguments
provided to the dispatcher gesture handler.

Fixes #11684.

Is there anything you want to mention? (unchecked code, possible bugs, found problems, breaking compatibility, etc.)

An alternative implementation could be to join the already parsed arguments with the , separator. But using the original string feels more portable, e.g., in case future dispatchers may depend on whitespace, etc.

Is it ready for merging, or does it need work?

Hopefully, ready for merge!

[kolayne]

Huh. The code style pipeline fails for a line that I never edited.

[kolayne]

@vaxerski, ahh, unfortunately, this MR breaks something. Consider the line:

gesture = 4, left, dispatcher, movefocus, l

According to the code, we find the last comma and take the first character after it, which is a space. The moveFocusTo function ends up receiving the string " l", and the first character of it is not recognized as a direction, so the binding does not work.

I want to submit a fix, but I am not sure which function's fault is it: are dispatchers supposed to handle whitespaces, so we need to update moveFocusTo? Or is it config manager's responsibility to strip whitespaces?

[kolayne]

I can see that CVarList and CConstVarList have join methods, so we can keep the parsing logic there and just join the rest of the arguments parsed with the gesture keyword. I will do that.

However, should dispatcher functions accept std::string at all? Maybe it makes more sense to instead accept a range of parsed strings, in the form of a CVarList/CConstVarList or a pair of iterators over std::string_view, etc?