Propagate pooled arrays to RlpStream

[benaadams]

Follow up to Perf/poolable triestore #6022

Changes

• Propagate pooled arrays to RlpStream, by having is backing storage be CappedArray<byte>; rather than have it create an array if the pooled array is not same size as data.
• Pre-generate encoded array for numeric keys 0 to 1024 and reuse those rather than regenerating each time.
• Enclose the temp trie methods TxTrie.CalculateRoot, ReceiptTrie.CalculateProof, TxTrie.CalculateRoot, ReceiptTrie.CalculateProof in static method using the pooling and switch everything over to use them; rather than multistep unpooled.

Left before, right after

Types of changes

What types of changes does your code introduce?

• Optimization

Testing

Requires testing

• No