BREAKING: Rename Call & Event (#11981)

* rename Event to RuntimeEvent

* rename Call

* rename in runtimes

* small fix

* rename Event

* small fix & rename RuntimeCall back to Call for now

* small fixes

* more renaming

* a bit more renaming

* fmt

* small fix

* commit

* prep for renaming associated types

* fix

* rename associated Event type

* rename to RuntimeEvent

* commit

* merge conflict fixes & fmt

* additional renaming

* fix.

* fix decl_event

* rename in tests

* remove warnings

* remove accidental rename

* .

* commit

* update .stderr

* fix in test

* update .stderr

* TRYBUILD=overwrite

* docs

* fmt

* small change in docs

* rename PalletEvent to Event

* rename Call to RuntimeCall

* renamed at wrong places :P

* rename Call

* rename

* rename associated type

* fix

* fix & fmt

* commit

* frame-support-test

* passing tests

* update docs

* rustdoc fix

* update .stderr

* wrong code in docs

* merge fix

* fix in error message

* update .stderr

* docs & error message

* .

* merge fix

* merge fix

* fmt

* fmt

* merge fix

* more fixing

* fmt

* remove unused

* fmt

* fix

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>