Log metric data points in logging exporter

[nilebox]

Description:
Log metric data points in logging exporter.
Currently only resource labels are being logged.

Link to tracking Issue: -

Testing: Unit tests + tested manually:

ResourceMetrics #0
Resource labels:
     -> resource-attr: STRING(resource-attr-val-1)
InstrumentationLibraryMetrics #0
Metric #0
Descriptor:
     -> Name: counter-int
     -> Description: 
     -> Unit: 1
     -> Type: MONOTONIC_INT64
Int64DataPoints #0
Data point labels:
     -> label-1: label-value-1
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Value: 123
Int64DataPoints #1
Data point labels:
     -> label-2: label-value-2
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Value: 456
Metric #1
Descriptor:
     -> Name: counter-double
     -> Description: 
     -> Unit: 1
     -> Type: MONOTONIC_DOUBLE
DoubleDataPoints #0
Data point labels:
     -> label-1: label-value-1
     -> label-2: label-value-2
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Value: 1.230000
DoubleDataPoints #1
Data point labels:
     -> label-1: label-value-1
     -> label-3: label-value-3
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Value: 4.560000
Metric #2
Descriptor:
     -> Name: cumulative-histogram
     -> Description: 
     -> Unit: 1
     -> Type: HISTOGRAM
HistogramDataPoints #0
Data point labels:
     -> label-1: label-value-1
     -> label-3: label-value-3
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Count: 1
Sum: 15.000000
HistogramDataPoints #1
Data point labels:
     -> label-2: label-value-2
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Count: 1
Sum: 15.000000
Buckets #0, Count: 0
Buckets #1, Count: 1
ExplicitBounds #0: 1.000000
Metric #3
Descriptor:
     -> Name: summary
     -> Description: 
     -> Unit: 1
     -> Type: SUMMARY
SummaryDataPoints #0
Data point labels:
     -> label: label-value-1
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Count: 1
Sum: 15.000000
SummaryDataPoints #1
Data point labels:
     -> label: label-value-2
StartTime: 1581452772000000321
Timestamp: 1581452773000000789
Count: 1
Sum: 15.000000
ValueAtPercentiles #0, Value: 15.000000, Percentile: 1.000000

Documentation: -

[bogdandrutu]

Please fix the lint errors

[codecov]

Codecov Report

Merging #1258 into master will increase coverage by 0.09%.
The diff coverage is 97.56%.

@@            Coverage Diff             @@
##           master    #1258      +/-   ##
==========================================
+ Coverage   88.50%   88.60%   +0.09%     
==========================================
  Files         207      207              
  Lines       14945    15109     +164     
==========================================
+ Hits        13227    13387     +160     
- Misses       1286     1288       +2     
- Partials      432      434       +2     

Impacted Files	Coverage Δ
exporter/loggingexporter/logging_exporter.go	89.17% <95.55%> (+5.48%)	⬆️
internal/data/testdata/metric.go	100.00% <100.00%> (ø)
translator/internaldata/resource_to_oc.go	81.39% <0.00%> (-2.33%)	⬇️

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[nilebox]

@bogdandrutu added logging for data point values, fixed lint errors, increased code coverage.