feat: experimental-monitor-multi-block support

[niklasad1]

This PR adds support for the multi-block pallet which is added as new monitor command experimental-monitor-multi-block

Thus, the "old miner a.k.a single-block miner" isn't modified and should work as it did before.

To run the experimental multi-block command can be done as follows:

polkadot-staking-miner --uri ws://127.0.0.1:9966 experimental-monitor-multi-block --seed-or-path //Alice

Manual testing done:

• Mining, submitting solution, pages and rewarded works against [AHM] Multi-block staking election pallet polkadot-sdk#7282
• Get it tested against [DNM] Add AH-next runtime - the post-migration Asset Hub runtime polkadot-sdk#6996, see multi block: testing against asset-hub-next #986

Things to improve (possibly after merging):

• Proper integration test against the parachain assethub-next
• Make the NPoS algorithm configurable
• Prometheus metrics
• Double check hardcoding values (worth looking into whether we can utilize metadata v16 to improve that)
• Check verification after pages submitted
• Currently the code only checks that no better scores exist on chain and that the miner hasn't submitted yet.
  This is not sufficient because we must also make sure that all pages have been submitted if requested.
  AFAIU, otherwise the miner may be slashed

Extra notes for reviewer, lots of code is changed due to refactoring but the most important parts is:

• commands/multi-block/monitor.rs: which contains the logic how the snapshot/signed phase are handled.

[niklasad1]

fix before merge

[kianenigma]

Some todos:

• You can use SubmissionMetadata to know if you have submitted
• You can fetch the snapshot at any time, no need to sync with inner in Phase::Snapshot(inner).
• Atm we are bailing too much, if half finished, complete it
• Once round is over, if our submission is not the best, do the refund via clear_old_round_data.