Update to OTLP proto 0.12.0

[tigrannajaryan]

Resolves #4717

• Removed all deprecated metric messages and corresponding conversion code and tests.
• Removed deprecated_code from span status and corresponding conversions and tests.
• Renamed logs field to log_records in InstrumentationLibraryLogs message.

[codecov]

Codecov Report

Merging #4724 (165ecee) into main (105f75b) will decrease coverage by 0.05%.
The diff coverage is 81.48%.

@@            Coverage Diff             @@
##             main    #4724      +/-   ##
==========================================
- Coverage   90.73%   90.68%   -0.06%     
==========================================
  Files         179      179              
  Lines       10696    10541     -155     
==========================================
- Hits         9705     9559     -146     
+ Misses        770      763       -7     
+ Partials      221      219       -2     

Impacted Files	Coverage Δ
model/internal/otlp_wrapper.go	100.00% <ø> (+7.97%)	⬆️
model/pdata/traces.go	91.66% <ø> (-2.46%)	⬇️
model/pdata/logs.go	82.14% <20.00%> (-13.70%)	⬇️
model/pdata/generated_log.go	96.65% <93.33%> (ø)
internal/otlptext/logs.go	100.00% <100.00%> (ø)
model/pdata/generated_trace.go	96.89% <100.00%> (+0.01%)	⬆️
processor/batchprocessor/splitlogs.go	100.00% <100.00%> (ø)

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[tigrannajaryan]

@open-telemetry/collector-approvers please review the deletions of metrics code carefully. I want to make sure I didn't break anything and didn't delete any code that was supposed to stay.

[Aneurysm9]

It gets a bit hard to follow the changes in the generated *.pb.go files, but it looked like the metrics changes were what I'd expect. The deprecated types were removed and from there it looked like noise from shuffling things around.

[codeboten]

I think the changes all look good, I'd like to merge this after this next release though

[tigrannajaryan]

I think the changes all look good, I'd like to merge this after this next release though

Yes, let's hold this until the release is done.