Make instant seal work and added interval

[girazoki]

Description

This PR fixes Instant seal which was not working because consensus_providers were not being passed and also adds interval sealing, which will create a block at the defined interval.

Instant sealing works better when offchain workers are disabled, as the offchain worker creates txs by itself.

Example usages:

./target/release/node-subtensor --dev --tmp --sealing=instant --offchain-worker never

./target/release/node-subtensor --dev --tmp --sealing=6000

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Other (please describe):
  More flexibility when testing

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have run ./scripts/fix_rust.sh to ensure my code is formatted and linted correctly
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Screenshots (if applicable)

Please include any relevant screenshots or GIFs that demonstrate the changes made.

Additional Notes

Please provide any additional information or context that may be helpful for reviewers.