Add Transaction Merchant management (#686)

* Add basid crud for merchant management

* Tweak UI and add localization

* Fix lint

* Add filtering by merchant

* Add tests

* Add stimulus controller to update avatar in merchant form

* Add line between merchant rows

* Change default merchant color

* Cleanup

db/migrate/20240426191312_add_transaction_merchants.rb

@@ -0,0 +1,13 @@
+class AddTransactionMerchants < ActiveRecord::Migration[7.2]
+  def change
+    create_table :transaction_merchants, id: :uuid do |t|
+      t.string "name", null: false
+      t.string "color", default: "#e99537", null: false
+      t.references :family, null: false, foreign_key: true, type: :uuid
+
+      t.timestamps
+    end
+
+    add_reference :transactions, :merchant, foreign_key: { to_table: :transaction_merchants }, type: :uuid
+  end
+end