⚡ [Datastore] Reduce the number of queries to keep the registry info updates

[dseurotech]

This pr adds a configuration switch that allows to skip a costly (and potentially unneccesary) fetch from elasticsearch currently performed for each metric not present in the cache (very inefficient in case of device messages with a lot of metrics).
The behaviour can me configured by the following parameter:
datastore.cache.metrics.fetchBeforeUpsert=true
omit the configuration or leave at 'true' to maintain the current behaviour, set to 'false' to skip the fetch

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.

Project coverage is 52.30%. Comparing base (f15c972) to head (997258e).
Report is 11 commits behind head on release-1.7.x.

Additional details and impacted files

@@                 Coverage Diff                 @@
##             release-1.7.x    #4081      +/-   ##
===================================================
- Coverage            52.34%   52.30%   -0.05%     
  Complexity            1864     1864              
===================================================
  Files                 1633     1633              
  Lines                46163    46166       +3     
  Branches              4233     4234       +1     
===================================================
- Hits                 24165    24148      -17     
- Misses               20604    20623      +19     
- Partials              1394     1395       +1     

Files	Coverage Δ
...tastore/internal/setting/DatastoreSettingsKey.java	100.00% <100.00%> (ø)
...e/datastore/internal/MetricInfoRegistryFacade.java	65.42% <85.71%> (-0.30%)	⬇️

... and 11 files with indirect coverage changes