Cleanup labels parsing.

[cyriltovena]

Make sure we only use one type of labels parsing.
This just reduce the amount of code we have to maintain.

We can also now ensure that labels are sent to the ingester ordered, so no need for special equality.

Signed-off-by: Cyril Tovena cyril.tovena@gmail.com

[codecov-io]

Codecov Report

Merging #2929 (b5ee538) into master (049c7ac) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2929      +/-   ##
==========================================
- Coverage   61.76%   61.74%   -0.03%     
==========================================
  Files         181      181              
  Lines       14731    14710      -21     
==========================================
- Hits         9098     9082      -16     
+ Misses       4801     4797       -4     
+ Partials      832      831       -1     

Impacted Files	Coverage Δ
pkg/util/conv.go	72.72% <ø> (+22.72%)	⬆️
pkg/distributor/distributor.go	75.91% <100.00%> (ø)
pkg/distributor/validator.go	90.24% <100.00%> (ø)
pkg/ingester/instance.go	56.62% <100.00%> (-0.18%)	⬇️
pkg/ingester/mapper.go	93.10% <100.00%> (+4.06%)	⬆️
pkg/ingester/transfer.go	58.91% <100.00%> (ø)
pkg/querier/queryrange/downstreamer.go	95.29% <0.00%> (-2.36%)	⬇️
pkg/logql/evaluator.go	91.24% <0.00%> (-0.41%)	⬇️