Undo removing migration checks

[Ank4n]

Re add the migration pre and post checks that was removed for PR https://github.com/paritytech/substrate/pull/12230.

With @ruseinov's fix for sequential execution of migrate functions https://github.com/paritytech/substrate/pull/12319, we do not need to do this hack anymore.

[Ank4n]

/cmd queue -c fmt $ 1

[command-bot[bot]]

@Ank4n https://gitlab.parity.io/parity/mirrors/substrate/-/jobs/1873093 was started for your command "$PIPELINE_SCRIPTS_DIR/fmt.sh" 1. Check out https://gitlab.parity.io/parity/mirrors/substrate/-/pipelines?page=1&scope=all&username=group_605_bot to know what else is being executed currently.

Comment /cmd cancel 42-7f6cd7a7-6e08-4aea-bd50-01db0a94212c to cancel this command or /cmd cancel to cancel all commands in this pull request.

[command-bot[bot]]

@Ank4n Command "$PIPELINE_SCRIPTS_DIR/fmt.sh" 1 has finished. Result: https://gitlab.parity.io/parity/mirrors/substrate/-/jobs/1873093 has finished. If any artifacts were generated, you can download them from https://gitlab.parity.io/parity/mirrors/substrate/-/jobs/1873093/artifacts/download.

[kianenigma]

just a minor note: https://github.com/paritytech/substrate/blob/master/docs/CONTRIBUTING.adoc#rules

[Ank4n]

just a minor note: https://github.com/paritytech/substrate/blob/master/docs/CONTRIBUTING.adoc#rules

Noted

[Ank4n]

bot rebase

[paritytech-processbot[bot]]

Rebased

[Ank4n]

bot merge