Resolve last address conflicts

[ghost]

Description

Provide last address conflict resolution and return timestamp in the LastTransactionAddress.
So changes in the chain index database are required.

Fixes #520

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

To test this feature, you start a node. Create a transaction on chain (for example AEWeb)
Then add another node, await the node replicate the transaction in the self-repair and become available (yet not authorized)
Then create another transaction on the chain. (the transaction should be replicated on the first node)
Then request the last update of the chain, the latest value should be retrieved while being called to the both nodes and the conflict resolutions should happen.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• 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