[influxdb/v2] inconsistent influxql result compared to 1.x

An external reporter sent an issue regarding an anomaly with InfluxQL queries in 2.x. Using 2.7.6, I found that the following influxql queries give different results from InfluxDB 1.8.10 and 1.11.5+git.

Eg, in 2.7.6, we see a partial result with one query:
```
$ export V1AUTH=$(echo -n "anything:$TOKEN" | base64 --wrap 0)

# generate some line protocol
$ cat > file.lp <

Start by reproducing the supplied line-protocol writes and InfluxQL queries against InfluxDB 2.7.6, then compare the CSV results with the stated 1.x versions. Trace the query path responsible for tag predicates and determine what behavior is expected; done means the second query returns the complete result set without regressing the first query.

Written by the indexing model from the issue text.