NXM total stake - account for stake burns

[tomfutago]

No description provided.

[tomfutago]

asked to update events:

• add active_stake to individual events (deposit, deposit extended, withdraw)
• emit "global" events on burns and expirations - also store active_stake

with added active_stake it will be easier to recreate the full history within a given pool.

with current available data it's not easy to calculate the history, mainly because of deposit extensions that shift active stake to different tranche (covered by recursive CTE currently) - in scenarios when this shift happens after previous stake burn.