Add `transaction_version` bump check

[bkchr]

We should write some CI job that checks if we need to bump the transaction_version. Subwasm and polkadot-js can help with this, but both currently don't provide any "perfect" solution AFAIK.

[bkontur]

@EgorPopelyaev uses some semi-manual script for testnets, maybe it could be useful also here for CI

[bkontur]

@bkchr can we close now?