Basic transaction categories CRUD actions (inline) (#601)

* Fix dropdown issues and add dummy transaction category modal

* Minor namings tweaks

* Add search type

* Use new menu controller

* Complete basic transaction category inline CRUD actions

* Fix lint error

---------

Co-authored-by: Jakub Kottnauer <jk@jakubkottnauer.com>

test/controllers/transactions/categories_controller_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class Transactions::CategoriesControllerTest < ActionDispatch::IntegrationTest
+  # test "the truth" do
+  #   assert true
+  # end
+end