Add trace anonymizer prorotype

[yurishkuro]

The anonymizer is used to obfuscate production traces before sharing them with academics.

Moving code from Uber's internal repo. The binary does not do anything yet, it needs to be wired with a source of spans, e.g. the Uber version tails production Kafka stream until it sees N spans.

[codecov]

Codecov Report

Merging #2328 into master will decrease coverage by 0.55%.
The diff coverage is 93.33%.

@@            Coverage Diff             @@
##           master    #2328      +/-   ##
==========================================
- Coverage   96.21%   95.65%   -0.56%     
==========================================
  Files         203      205       +2     
  Lines       10291    10529     +238     
==========================================
+ Hits         9901    10072     +171     
- Misses        334      391      +57     
- Partials       56       66      +10     

Impacted Files	Coverage Δ
plugin/storage/integration/trace_compare.go	36.58% <ø> (ø)
plugin/storage/integration/integration.go	80.38% <92.85%> (ø)
plugin/storage/es/factory.go	100.00% <100.00%> (ø)
plugin/storage/badger/spanstore/reader.go	96.15% <0.00%> (-0.65%)	⬇️
cmd/query/app/static_handler.go	85.83% <0.00%> (+1.66%)	⬆️

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