exported datasink results are not being broken by build variants

[filipecosta90]

Right now we have mixed results for each build variant on the same time-series given we're not breaking by it.
Example (containing 1 GCC + 3 ICC numbers ) :
PS: numbers might be off and we might need to check why,etc...

benchmarks.redislabs.com:12011> ts.range  "ci.benchmarks.redislabs/by.branch/ci/redis/redis/redis-benchmark-full-suite-1Mkeys-100B/oss-standalone/benchmarks.api/rps/ZPOPMIN" - + 
1) 1) (integer) 1629306470835
   2) 132978.73
2) 1) (integer) 1629306526350
   2) 99800.4
3) 1) (integer) 1629306581569
   2) 200000
4) 1) (integer) 1629306632933
   2) 200000