Refactored to rename "service terms" to "terms of service" (#9581)

* #124 renamed identififers from service terms to terms of service

* #124 renamed identififers from service terms to terms of service

* 124 renamed ServiceTerms model to TermsOfService

* 124 Renamed EnableCustomServiceTerms feature flag to EnableCustomTermsOfService

* 124 Renamed EnableCustomServiceTerms feature flag to EnableCustomTermsOfService

* #124 fixed formatting

* #124 fixed formatting

* #132 renamed table ServiceTerms to TermsOfService

* #124 renamed some missed files from 'service_terms' to 'terms_of_service'

* #124 removed fixed TODOs

* drop migrate of ServiceTerms table, since backporting

* s/ServiceTerms/TermsOfService/ in tests

* s/AcceptedServiceTermsId/AcceptedTermsOfServiceId/

Change the model attribute, even though the column name will eventually be removed.

* s/accepted_service_terms_id/accepted_terms_of_service_id/ to match redux

* s/serviceTerms/termsOfService

* rename column too, and add max size constraint

* s/EnableCustomServiceTerms/EnableCustomTermsOfService

store/sqlstore/store.go

@@ -93,5 +93,5 @@ type SqlStore interface {
 	UserAccessToken() store.UserAccessTokenStore
 	Role() store.RoleStore
 	Scheme() store.SchemeStore
-	ServiceTerms() store.ServiceTermsStore
+	TermsOfService() store.TermsOfServiceStore
 }