4.7.4

Encryption fields added to moodle config (#1889)

* feat: added fields for holding encrypted data in database (ENT 5613)

* refactor: removing "null=true" constraint from encrypted fields

* refactor: changing version for pull request merge

* fix: used null=True to avoid decryption of empty values

* refactor: removed unused import

* refactor: D000 Title underline too short

* refactor: added more meaningful help text for encryption fields

* fix: added missing updated migration

* fix: corrected change log file