datastore driver - adding reconnect to datastore capabilities

[riccardomodanese]

Signed-off-by: riccardomodanese riccardo.modanese@eurotech.com
There is no way to start the broker if ElasticSearch is down at startup. The broker is expected to start even if ES is down. The connection with the data-store should be tried periodically, until it has been established

Related Issue
none

Description of the solution adopted
No exception is thrown if an error occurred when establishing the data-store connection. A connection task is then executed periodically until the connection is established.

Screenshots
none

Any side note on the changes made
none

[riccardomodanese]

Note:
Since the Elastisearch transport client is deprecated since a while and it will be removed soon, the deprecated tag is added to the Kapua transport datastore client objects (the rest client should be used instead).
For this reason the changes of this pr are affecting only the Rest client. The transport client behavior remains at it was before.

[codecov]

Codecov Report

Merging #2969 into develop will increase coverage by 0.38%.
The diff coverage is 47.45%.

@@              Coverage Diff              @@
##             develop    #2969      +/-   ##
=============================================
+ Coverage      56.19%   56.58%   +0.38%     
- Complexity      2591     2601      +10     
=============================================
  Files           1061     1061              
  Lines          23002    22938      -64     
  Branches        2064     2043      -21     
=============================================
+ Hits           12926    12979      +53     
+ Misses          9123     9013     -110     
+ Partials         953      946       -7     

Impacted Files	Coverage Δ	Complexity Δ
...re/client/transport/EsTransportClientProvider.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...ore/client/transport/TransportDatastoreClient.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...service/datastore/internal/MessageStoreFacade.java	49.10% <ø> (ø)	16.00 <0.00> (ø)
...astore/internal/client/DatastoreClientFactory.java	48.27% <ø> (ø)	3.00 <0.00> (ø)
...ce/datastore/client/rest/EsRestClientProvider.java	30.63% <54.28%> (+5.10%)	17.00 <4.00> (+4.00)
...ice/datastore/client/rest/RestDatastoreClient.java	68.40% <94.59%> (+6.94%)	60.00 <28.00> (-3.00)	⬆️
...rvice/datastore/client/rest/ClientSettingsKey.java	100.00% <100.00%> (ø)	3.00 <0.00> (ø)
.../jbatch/persistence/JPAPersistenceManagerImpl.java	31.60% <0.00%> (+1.03%)	30.00% <0.00%> (ø%)
...apua/job/engine/jbatch/JobEngineServiceJbatch.java	51.85% <0.00%> (+1.85%)	8.00% <0.00%> (ø%)
... and 12 more