Add Ability to Add/Remove Invulnerable Collators (#2596)

* add add and remove invulnerable dispatchables

* add migration

* fix benchmarking code

* add weights

* add migration to runtimes

* clippy

* pass SafeCallFilter

* make try-runtime work

* typos

Co-authored-by: Ankan <[email protected]>

* better insert and added test

* fix try-runtime update

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <[email protected]>

* Update pallets/collator-selection/src/migration.rs

* check events in test

* Update pallets/collator-selection/src/migration.rs

Co-authored-by: Kian Paimani <[email protected]>

* just dispatchresult

* only sp_std for try-runtime

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Co-authored-by: Ankan <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Kian Paimani <[email protected]>