Improve JS method regex in ctags config

[nathansobo]

This allows function calls as default parameter values by loosening the regex to allow closing parentheses within a method parameter list. Can't think of how this would create false positives so we'll give this a try.

It also excludes switch and with flow control constructs from being matched as if they were methods.

[maxbrunsfeld]

Waiting on review from @50Wliu.

[50Wliu]

Turns out I was thinking of a different but visually similar regex. I don't see any problems with this one.