x{stake,slash,gov,distrib} In-place Store Migrations (#8504)

* Add 1st version of migrate

* Put migration logic into Configurator

* add test to bank store migration

* add test for configurator

* Error if no migration found

* Remove RunMigrations from Configurator interface

* Update spec

* Rename folders

* copy-paste from keys.go

* Fix nil map

* rename function

* Update simapp/app.go

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

* Update simapp/app_test.go

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

* Adderss reviews

* Fix tests

* Update testutil/context.go

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

* Update docs for ConsensusVersion

* Rename to forVersion

* Fix tests

* Check error early

* Return 1 for intiial version

* Use MigrationKeeper

* Fix test

* Revert adding marshaler to Configurator

* Godoc updates

* Update docs

* Add distrib legacy folder

* Add tests for distrib migration

* Add gov migrations

* Copy paste whole keys file

* Add gov migrations

* Add staking

* Fix staking tests

* Update spec and module.go

* Update to latest changes

* Update migration scripts

* capability to 1

* Fix tests

* Add package godoc

* Remove whitespace

* Remove global

* Use Migrator

* Remove 042 keys files

* Fix build

* Unlambda

* Rename to Migrate1to2

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

types/module/module.go

@@ -331,7 +331,7 @@ func (m *Manager) ExportGenesis(ctx sdk.Context, cdc codec.JSONMarshaler) map[st
 }
 
 // MigrationHandler is the migration function that each module registers.
-type MigrationHandler func(store sdk.Context) error
+type MigrationHandler func(sdk.Context) error
 
 // MigrationMap is a map of moduleName -> version, where version denotes the
 // version from which we should perform the migration for each module.