fix issue with projection __time equivalent column mapping

[clintropolis]

Description

Fixes some issues with project __time column remapping. The first issue is that a projection with finer granularity would incorrectly replace a coarser granularity time_floor function with the projection __time column, instead of retaining the time_floor operation to further rollup the projection at query time, producing incorrect results. The added test covers this. Fixing this stumbled into another issue with remapping the __time column when it was the same as the projection granularity, which would incorrectly map the matching query virtual column to the internal projection time column name instead of to __time itself. idk what i was thinking with the previous logic 🤷

[cecemei]

i thought this meant query has a sortBy at first, but i guess here's just we want to test out time as granularity & virtual column? might worth some comments.

[cecemei]

also, some projections are named as daily, e.x. abfoo_daily but it's not grouping by DAY right?

[clintropolis]

i thought this meant query has a sortBy at first, but i guess here's just we want to test out time as granularity & virtual column? might worth some comments.

yea, sortByDim is whether or not the segment we are querying is stored sorted first by __time or not, its one of the test parameters which controls if we set the forceSegmentSortByTime parameter on DImensionsSpec added in #16849. When this is set, using a granularity on a query doesn't work because the assumptions the engines make about the segments when using granularity (which acts like an implicit group by time_floor(__time, granularity)) are that the rows of the cursor are ordered by __time and so it can just scan and collect the time bucket group of the granularity as it goes instead of grouping on it properly as if it were a dimension. So for group by, we have to explicitly make a time_floor and group on it instead of using the query granularity. Timeseries queries don't work either if the segment isn't first sorted by __time, so some of the tests also just skip if the segment isn't time sorted. I can rename this parameter to segmentSortedByTime or something and it might be clearer?

also, some projections are named as daily, e.x. abfoo_daily but it's not grouping by DAY right?

ah I guess I could rename them to leave the granularity off of the implicit ones, some of those are projections without a __time equivalent column, but they still live within the constraints of the segment granularity, so its an implicit time_floor of day in this case since that is when the segment interval starts.