R1:4cb62ca0d6ae

Support "phriction.document.search" queries by "parentPaths" or "ancestorPaths"

Summary: Ref T13090. Ref T13077. This adds `parentPaths` and `ancestorPaths` constraints to `phriction.document.query`. These should be a little more usable than the internal `slugPrefix` / `depth` stuff -- that's technically more powerful, but requires callers to know more slug normalization rules. We could perhaps expose `minDepth` / `maxDepth` in the future.

Test Plan: Ran valid and invalid `parentPaths` and…