[Pallets] Execute migrations for parachain-staking

[sea212]

Execute all parachain-staking migrations (between a1956695d7eeb83f095908b56cce3b3e69e039c4 and 45257659f04b28dd4927b5dc611fac6f9e8905fd

Relevant migrations:

• [Staking] Kill unnecessary storage bloat moonbeam-foundation/moonbeam#970
• [Staking] Make exits manual, patch lack of delay for {increasing, decreasing} bonds moonbeam-foundation/moonbeam#810
• [Staking] Increase max delegations per candidate moonbeam-foundation/moonbeam#1096 - irrelevant, since the list bottom_candidates is empty on our live chains (to be more precise, no bottom candidates exist that have to be moved top candidates)

[4meta5]

@sea212 All 3 migrations are not related so they can be executed in the same block if necessary. Uncomment the required migrations and functions if they are used in the migration.

I don't see where the migrations are used in #458 , moonbeam uses pallet-migrations instead of on_runtime_upgrade in the pallet so these migrations are not executed by default if you do not have pallet-migrations in your runtimes.

[sea212]

@4meta5 Thanks a lot for the input. So I assume the following way is a valid and error-free approach: We create a fork, uncomment the migration that's commented out, and apply all migrations specified in this issue by adding the respective structs that implement OnRuntimeUpgrade to the Executive type.

[4meta5]

That should work. If you have any trouble with it, feel free to ping me on Riot.