grpc for node and support for new proto format for node and browser

[obecny]

Which problem is this PR solving?

• Fixes Send data to opentelemetry-collector using grpc for node only #567
• Fixes Use OTLP format instead of OpenCensus for OTLP exporter  #854

Short description of the changes

• It adds grpc for node
• It uses new proto format for browser and node

Bear in mind that currently there is no yet opentelemetry collector that supports grpc and new format, this needs to wait until this is done
it is there now, tested and fixed

[codecov-io]

Codecov Report

Merging #901 into master will decrease coverage by 0.25%.
The diff coverage is 78.49%.

@@            Coverage Diff             @@
##           master     #901      +/-   ##
==========================================
- Coverage   94.94%   94.69%   -0.26%     
==========================================
  Files         247      247              
  Lines       11142    11228      +86     
  Branches     1065     1077      +12     
==========================================
+ Hits        10579    10632      +53     
- Misses        563      596      +33     

Impacted Files	Coverage Δ
...es/opentelemetry-exporter-collector/test/helper.ts	68.47% <67.04%> (-31.53%)	⬇️
.../opentelemetry-exporter-collector/src/transform.ts	86.07% <85.07%> (-3.67%)	⬇️
...emetry-exporter-collector/src/CollectorExporter.ts	90.47% <90.00%> (-0.83%)	⬇️
...ages/opentelemetry-exporter-collector/src/types.ts	100.00% <100.00%> (ø)
...es/opentelemetry-exporter-collector/src/version.ts	0.00% <0.00%> (-100.00%)	⬇️

[mayurkale22]

@open-telemetry/javascript-approvers Please review when you get a chance.

[obecny]

Wait with more reviews as I can't make it work with latest otel anyway - will let you know where is the problem when I finish

[dyladan]

Requesting changes so this doesn't get accidentally merged while @obecny is still working on it.

[mayurkale22]

Added first pass comments.

[mayurkale22]

@obecny why do you think this one has breaking changes?

[obecny]

@obecny why do you think this one has breaking changes?
because you won't be able to use the new version with old collector - format is different and grpc is being used instead of http

[dyladan]

I agree with @obecny on breaking from the standpoint that if you have a previously running collector that we are exporting to and you update with this PR version, it may stop working.

[mayurkale22]

Overall LGTM. Honestly, PR is very big, easy to miss things. I would like to give another pass before approving.