Use better_errors editor links in sherlock

Closes #18254. Uses the same editor configuration of `better_errors`
so that you don't have to configure things twice. Remember to have a
custom initializer that specifies your editor.

Example for atom. File `config/initializers/better_errors.rb`:
````ruby
if defined?(BetterErrors)
  BetterErrors.editor = "atm://open?url=file://%{file}&line=%{line}"
end
````

See merge request !4497