PIP-22: Stake-weighted Servicer Rewards

[iaa12 (Jim Smith)]

@Andy-Liquify

The previous conversation on weighted staking have always been about weighting session chance, however this is not an easy thing to achieve it is very complex and adds a lot of state data to keep track of everything.

I have introduced PIP-23 -Stake Weighted Algorithm for Node Selection (SWANS) which aims to create a simple node selection algorithm based on stake amount. It is only a few lines of code, easy to understand, maintains no state, and preserves the pseudorandom nature of the current cherry picker - it preserves the current logic in its entirety, as it’s only a transformation to the list of servicer nodes. Any feedback welcome.