Chore: Enable Users to create multiple accounts (#440)

Addresses: #402
- migrations to split roles and other attributes from users table
- make changes in code to accommodate this change

Co-authored-by: Sojan Jose <sojan@pepalo.com>
Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>

app/views/api/v1/profiles/update.json.jbuilder

@@ -4,7 +4,7 @@ json.uid @user.uid
 json.name @user.name
 json.nickname @user.nickname
 json.email @user.email
-json.account_id @user.account_id
+json.account_id @user.account.id
 json.pubsub_token @user.pubsub_token
 json.role @user.role
 json.confirmed @user.confirmed?