Proto: Disable the `Set_deposits_limit` if autostaking is off (Follow-up from "Revert "Proto: remove operation Set_deposits_limit"")

The following discussion from !10449 (merged) should be addressed:

• @mbouaziz started a discussion: (+3 comments)

  1. We should disable the Set_deposits_limit if autostaking is off

  2. We should fail if the given amount is less minimal_frozen_stake?