Make TTL configurable via config and reconcile it

[leoluk]

We currently default to 1 week and tell users to customize it using alter table default.flows_raw modify ttl Date + toIntervalDay(20).

https://github.com/monogon-dev/NetMeta/blob/2bab7d91da7c8fd97e8a414989f42c8b8dfd2b69/deploy/single-node/schema/0001_create_flows_raw.sql#L79

Now that we auto-reconcile, we should make this a config item and have the reconciler apply it automatically (+making sure it gets applied to old partitions, maybe CH even does this automatically now).

[fionera]

This is harder than it seems as we have to prevent users to accidentally nuke all their data. My current Idea is to move all operations to the reconciler including the creation of flows_raw but still keep migrations around for destruction of things. Also if the reconciler wants to reduce the ttl, delete anything etc. it should cancel and throw a warning.

Maybe we can create a table where we write log messages into and display them inside grafana to not have the user run in the dark?