feat: Update API for contact avatar (#4719)

Added the ability to update the contact's avatar via API and Dashboard.

- Contact create and update APIs can now accept avatar attachment parameters [form data].
- Contact create and update endpoints can now accept the avatar_url parameter.[json]
- API endpoint to remove a contact avatar.
- Updated Contact create/edit UI components with avatar support

Fixes: #3428

app/javascript/dashboard/api/specs/contacts.spec.js

@@ -12,6 +12,7 @@ describe('#ContactsAPI', () => {
     expect(contactAPI).toHaveProperty('delete');
     expect(contactAPI).toHaveProperty('getConversations');
     expect(contactAPI).toHaveProperty('filter');
+    expect(contactAPI).toHaveProperty('destroyAvatar');
   });
 
   describeWithAPIMock('API calls', context => {
@@ -100,6 +101,13 @@ describe('#ContactsAPI', () => {
         queryPayload
       );
     });
+
+    it('#destroyAvatar', () => {
+      contactAPI.destroyAvatar(1);
+      expect(context.axiosMock.delete).toHaveBeenCalledWith(
+        '/api/v1/contacts/1/avatar'
+      );
+    });
   });
 });