feat: Support Regex validation for custom attributes (#7856)

This allows a user to add/update a custom regex and a cue while defining custom attributes(Only applicable for type- text).
While adding/editing custom attributes, the values are validated against the attribute definition regex, and if it is incorrect, a cue message or default error message is shown and restricts invalid values from being saved.

Fixes: #6866

db/migrate/20230905060223_add_regex_to_custom_attribute_definition.rb

@@ -0,0 +1,6 @@
+class AddRegexToCustomAttributeDefinition < ActiveRecord::Migration[7.0]
+  def change
+    add_column :custom_attribute_definitions, :regex_pattern, :string
+    add_column :custom_attribute_definitions, :regex_cue, :string
+  end
+end