WIP: Handle single pivot update + single peer; allow long non-finality

[flcl42]

Changes

• Make use single pivot update in case of single peer: we update pivot block number in sync config once and if ;
• Allow long non finality: sync does not progress if most recent finalized block is more than 128 blocks ago, which seems to be normal for L2s (got a case of 2000 blocks)

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a change that causes existing functionality not to work as expected)
• Optimization
• Refactoring
• Documentation update
• Build-related changes
• Other: Description

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Notes on testing

Need to sync as many nets as possible

Documentation

Requires documentation update

• Yes - maybe we can mention one new setting
• No

Requires explanation in Release Notes

• Yes
• No

[marcindsobczak]

I'm trying with a different approach - to use head block minus 64 instead of finalized block. It will not be 100% safe, but in e.g. optimism there is no other option, as there is no finalized hash in FCU until fully synced
#7586

[flcl42]

I'm trying with a different approach - to use head block minus 64 instead of finalized block. It will not be 100% safe, but in e.g. optimism there is no other option, as there is no finalized hash in FCU until fully synced #7586

@marcindsobczak Sounds good! Let me test your approach with taiko. Wdyt about the second part of the pr that fixes the following?: when we have one peer and single fcu sent we can't start snapsync

[marcindsobczak]

@flcl42 current aproach is not working with one peer? Why?