Perf/optimize old bodies memory

[asdacap]

• Reduces memory allocation during OldBodies.
• Works by:
  • Slices Memory<byte> from netty buffer when deserializing Transaction.Data.
  • Slices Memory<byte> form netty buffer when setting Transaction._preHash.
  • Pool Transaction.
• Tried to make it a refstruct, but failed.

(after, before, after, before, after, before)

Changes

• Create OwnedBlockBodies which must be disposed.
• Modified block bodies message deserializer to slice Memory<byte>
• Modified TX decoder to use pooled Transaction object.

Types of changes

What types of changes does your code introduce?

• Optimization

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Mainnet bodies from ancient barriers to block 12572600 matches. Took too long to wait until head.