1. After moving read databases call to RP for Tables API, we lose the `_rid` property. Since we are reading Table's database offer with SDK, we need the `_rid` of the database to find its offer. Without `_rid`, we won't be able to find the database offer and the Scale tab would disappear again. The fix is to use SDK to read databases for Table API so we have `_rid`.
2. There's a bug in the non-aad code path for updating offers which prevents users from switching from manual to autoscale and vice versa. The fix is to properly set the option headers.
Since I've cleaned up all the places that use `_rid` and `_self` of a database in my previous commit (d525afa142), we are safe to use RP to read databases for all APIs except Tables.
For Tables API, since RP doesn't support any database level operations, I have to hardcode the read database response. The only property we need in the Tables database is the id which is the string that we display in the resource tree.
* Fix settings tab issue for cassandra and add feature flag
* Adding the rest of the changes....
Co-authored-by: Steve Faulkner <southpolesteve@gmail.com>
