Mapped new 'signed' property for INVENTORY-V1 Bundles

[Coduz]

This PR maps the new property added to the InventoryBundles by Kura in eclipse-kura/kura#3681

Related Issue
This PR adapts to the changes made in eclipse-kura/kura#3681

Description of the solution adopted
Added the new property and mappings

Screenshots
None

Any side note on the changes made
None

[codecov]

Codecov Report

Merging #3510 (0f4a14a) into develop (91d417f) will decrease coverage by 11.89%.
The diff coverage is 0.00%.

❗ Current head 0f4a14a differs from pull request most recent head 8e7b0df. Consider uploading reports for the commit 8e7b0df to get more accurate results

@@              Coverage Diff               @@
##             develop    #3510       +/-   ##
==============================================
- Coverage      49.60%   37.70%   -11.90%     
+ Complexity       259      184       -75     
==============================================
  Files           1646     1646               
  Lines          31647    31652        +5     
  Branches        2617     2617               
==============================================
- Hits           15697    11935     -3762     
- Misses         15044    19077     +4033     
+ Partials         906      640      -266     

Impacted Files	Coverage Δ
...a/model/inventory/bundles/KuraInventoryBundle.java	0.00% <0.00%> (ø)
...ory/TranslatorAppInventoryBundleExecKapuaKura.java	12.00% <0.00%> (-0.50%)	⬇️
...ntory/AbstractTranslatorAppInventoryKuraKapua.java	0.00% <0.00%> (-5.46%)	⬇️
.../kapua/service/tag/internal/TagListResultImpl.java	0.00% <0.00%> (-100.00%)	⬇️
...ua/service/datastore/internal/schema/Metadata.java	0.00% <0.00%> (-100.00%)	⬇️
.../service/datastore/internal/model/DataIndexBy.java	0.00% <0.00%> (-100.00%)	⬇️
...rvice/endpoint/internal/EndpointInfoQueryImpl.java	0.00% <0.00%> (-100.00%)	⬇️
...vice/datastore/internal/DatastoreCacheManager.java	0.00% <0.00%> (-100.00%)	⬇️
.../device/call/kura/model/keystore/KuraKeystore.java	0.00% <0.00%> (-100.00%)	⬇️
...e/datastore/internal/mediator/ClientInfoField.java	0.00% <0.00%> (-100.00%)	⬇️
... and 209 more