Allow new values in the add term dropdowns (Variable, Property, Trait Class, Method, Scale) when no exact match is searched in the select2 dropdown

GCP-10132

Reviewer: Crisjaira Villarino
Allow new values in the edit term dropdowns (Variable, Property, Trait Class, Method, Scale) when no exact match is searched in the select2 dropdown

GCP-10132

Reviewer: Crisjaira Villarino
Refactored initializeVariable method into small separate methods

GCP-10132

Reviewer: Crisjaira Villarino
Changed double quotes to single quotes for js strings, changed single quotes to double quotes for html attribute values

GCP-10132

Reviewer: Crisjaira Villarino
Add curly braces in if/else statements

GCP-10132

Reviewer: Crisjaira Villarino