Pass block tracker in deserialize block

[samliok]

Why this should be merged

Not having passing the blockTracker while deserializing a block causes nil pointer exceptions.

How this works

How this was tested

Need to be documented in RELEASES.md?

[Copilot]

Pull Request Overview

Fixes nil pointer exceptions in block deserialization by ensuring the blockTracker is properly passed to the deserializer. This addresses missing blockTracker initialization that was causing runtime failures when deserializing blocks.

• Updates blockDeserializer to include a blockTracker field
• Modifies DeserializeBlock to use newBlock() instead of direct Block struct creation
• Adds test verification to ensure deserialized blocks can be properly verified

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
simplex/block.go	Adds blockTracker field to blockDeserializer and updates DeserializeBlock to use newBlock()
simplex/block_test.go	Updates test to initialize blockTracker in deserializer and adds verification test

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