Tari's independent proof-of-work algorithm is very straightforward.

Calculate the _triple hash_ of the following input data:
 - Nonce (8 bytes)
 - Tari mining hash (32 bytes)
 - PoW record (for Sha-3x, this is always a single byte of value 1)

That is, the nonce in little-endian format, mining hash and the PoW record are chained together and hashed by the
Keccak Sha3-256 algorithm. The result is hashed again, and this result is hashed a third time. The result of the third
hash is compared to the target value of the current block difficulty.

A triple hash is selected to keep the requirements on hardware miners (FPGAs, ASICs) fairly low. But we also want to
avoid making the proof-of-work immediately "NiceHashable". There are several coins that already use a single or
double SHA3 hash, and we'd like to avoid having that hashrate immediately deployable against Tari.

This PR also stabilises RFC-0131

Description
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Updates the header version to change the PoW so we don't have to reset the chain

Motivation and Context
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See: #4862 

How Has This Been Tested?
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