Migrate find references to Rubydex (#4066)

* Fix parent scope and method receiver resolution and tracking

* Fix surrounding method call sites

* Add more parent scope and method definition receiver tests

* Migrate find references to Rubydex

Author: vinistock

lib/ruby_indexer/lib/ruby_indexer/reference_finder.rb

@@ -7,7 +7,6 @@
 require "ruby_indexer/lib/ruby_indexer/uri"
 require "ruby_indexer/lib/ruby_indexer/visibility_scope"
 require "ruby_indexer/lib/ruby_indexer/declaration_listener"
-require "ruby_indexer/lib/ruby_indexer/reference_finder"
 require "ruby_indexer/lib/ruby_indexer/enhancement"
 require "ruby_indexer/lib/ruby_indexer/index"
 require "ruby_indexer/lib/ruby_indexer/entry"