Reduce remote configuration error logging

[lloeki]

What does this PR do?

Reduce remote configuration error logging by:

• limiting to one error message per occurence of negotiation failure + type of failure
• moving transport level error reporting to debug level
• bubbling internal transport error responses to the level above so that they trigger the error path, with transport level information reporting via error logging

Motivation

When remote configuration counters an error state related to transport (typically agent unreachability or misconfiguration) it continuously retries, which results in a constant stream of errors.

Additional Notes

How to test the change?

• start an app
• start and stop the agent at various times

[codecov-commenter]

Codecov Report

Merging #3011 (88ce4d1) into master (7f1049c) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3011   +/-   ##
=======================================
  Coverage   98.08%   98.09%           
=======================================
  Files        1317     1317           
  Lines       74314    74363   +49     
  Branches     3397     3402    +5     
=======================================
+ Hits        72893    72944   +51     
+ Misses       1421     1419    -2     

Files Changed	Coverage Δ
lib/datadog/core/remote/client.rb	91.07% <100.00%> (+1.16%)	⬆️
lib/datadog/core/remote/component.rb	95.65% <100.00%> (+1.53%)	⬆️
lib/datadog/core/remote/negotiation.rb	100.00% <100.00%> (ø)
lib/datadog/core/transport/http/client.rb	100.00% <100.00%> (ø)
spec/datadog/core/remote/client_spec.rb	100.00% <100.00%> (ø)
spec/datadog/core/remote/component_spec.rb	100.00% <100.00%> (ø)
spec/datadog/core/remote/negotiation_spec.rb	100.00% <100.00%> (ø)
spec/datadog/core/transport/http_spec.rb	98.97% <100.00%> (+0.05%)	⬆️

... and 2 files with indirect coverage changes

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