Resolve VSN-2113 "Feature/improve circuit store state management and avenant auto-fill"
- Separate 'saving' and 'loading' states in circuitStore to prevent form fields from being disabled during list loading
- Auto-update avenant subject when actionType changes using prependNomPrenom
- Align USER_ADDRESS_CHANGE label with backend: 'Modification adresse usager' Closes VSN-2113