Allow `cmd_ctag` to use the current selection

[hovsater]

In Ruby, methods can end with ? and !. This makes the jump to tag functionality not work as it does not include the entire method name. It would be nice if I could manually select the entire method name and use the selection as input to cmd_ctag.

[adsr]

Hm we can add a regex mode to cursor_select_by that accepts a regex or maybe a mode that accepts an arbitrary set of characters. Then we can make cmd_ctag support a param that specifies which mode to use. On backlog.

[hovsater]

Yeah, I guess that's a more generalized solution to what I proposed. Makes sense. 👍