fix parenexpr and exemplars

fix mouse selector, label queries start+end, and offsets

upgrade prom fork to 2.30

race fixes and fix aggregate across multiple selectors

Fix error handling broken since v0.0.63

Fix series select handler, add form length option, fix MatrixSelector…

… downstream querying

Fix classic UI and /federate endpoint

fix panics in remote write

fix offsets within subqueries