ruby-ts-mode: Handle indent in parenless calls much closer to ruby-mode

ruby-ts-mode: Handle indent in parenless calls much closer to ruby-mode

* lisp/progmodes/ruby-ts-mode.el (ruby-ts--parent-call-or-bol):
New function.
(ruby-ts--indent-rules): Use it for cases which need special
anchoring logic when inside a parenless method call.
Remove the ad-hoc handling of pair-hash-pair etc indentation,
which was there only for the parenless cases, apparently.
Have "No paren, ruby-parenless-call-arguments-indent is nil" case
align to the statement, if only because ruby-mode does that.

* test/lisp/progmodes/ruby-ts-mode-tests.el:
Run indent test for ruby-parenless-call-arguments-indent.rb.