Filter initial extrinsics for Carthage rollout

[bedeho]

Background

While launching Carthage and mainnet, we wish to filter out any non-essential user actions, so as to avoid disrupting #3903 and to make relaunches more graceful, if required in a failure scenario.

Proposal

Using BaseFilter we drop all extrinsics unless they are for pallets

• sudo: so as to allow bootstrapping by Jsgensis and next runtime update
• staking: so as to allow user stake tokens and declare their intent to validate or nominate. Double check that this actually works and is the correct pallet to filter for this purpose, and nothing else is needed.

┆Issue is synchronized with this Asana task by Unito

[mnaamani]

Implementation in #3986