Create aliases for (long) search fields

[glampr]

Allow to alias (possibly long) search fields with (shorter) descriptions.
Works like ransacker, but uses already valid search fields, instead of requiring to write Arel.
Useful for converting long search fields to shorter, to save url length for GET requests.

Usage

class User
  translates :profile_text # from globalize gem
  has_many :works

  ransacker_alias :free_text, :translations_profile_text_or_works_translations_title_or_works_translations_description
end

User.search(free_text_cont: "some_text")
# same as User.search(translations_profile_text_or_works_translations_title_or_works_translations_description_cont: "some_text")

[houndci-bot]

Line is too long. [117/80]

[glampr]

Also mentioned in #253

[houndci-bot]

end at 16, 6 is not aligned with if at 12, 5

[jonatack]

Thanks for the contribution. Closed by #623.