Deprecated the bridge/opencensus/utils package

[MrAlias]

The opencensus package is defined to provide a migration bridge from OpenCensus to OpenTelemetry. It would follow that this package would contain all the translation functions for this purpose. Having a separate utils package only adds confusion about where things are. Give the package name is non-descriptive and there is no clear documentation about what purpose it has removing it and unify all OpenCensus bridging functionality in the opencensus package make sense.

Part of #2144

[codecov]

Codecov Report

Merging #2166 (dbf1599) into main (b1d1d52) will decrease coverage by 0.1%.
The diff coverage is 0.0%.

@@           Coverage Diff           @@
##            main   #2166     +/-   ##
=======================================
- Coverage   72.4%   72.3%   -0.2%     
=======================================
  Files        176     176             
  Lines      12091   12095      +4     
=======================================
- Hits        8765    8755     -10     
- Misses      3091    3102     +11     
- Partials     235     238      +3     

Impacted Files	Coverage Δ
bridge/opencensus/bridge.go	0.0% <0.0%> (ø)
bridge/opencensus/utils/utils.go	0.0% <ø> (ø)
sdk/metric/refcount_mapped.go	80.0% <0.0%> (-20.0%)	⬇️
...s/otlp/otlptrace/internal/connection/connection.go	14.8% <0.0%> (-1.6%)	⬇️
sdk/metric/sdk.go	79.5% <0.0%> (-1.5%)	⬇️