Replace ELS with internal LP volume asset

[davidsiska-vega]

Rip out ELS.

Instead each market will instantiate a new asset, uniquely tied to the market, called something like e.g. BTCUSD-Perp-LP (blobs / points/ shares / drops). Successor market doesn't create a new LP token asset and just uses the old one (needs some decimals worry).

• at the end of each epoch one token of the LP asset is minted for each unit of volume traded during the epoch and distributed pro-rata amongst LPs based on their SLA scores for the epoch.
• during the epoch the relative ownership of the LP tokens for the market amongst LPs is used as a weight instead of the ELS.
• have per-epoch inflation cap.