sonar critical throw a dedicated exception

sonar critical throw a dedicated exception

Define and throw a dedicated exception instead of using a generic one
Sonar Link:
https://sonar.onap.org/component_issues?id=org.onap.dcaegen2.platform%3Ainventory-api#resolved=false|severities=CRITICAL|assignees=Snigdha503415
Location:
src/main/java/org/onap/dcae/inventory/daos/InventoryDAOManager.java
Line No-143

Change-Id: I52ecbd360bff6efa8906623ae7345ef694491d6b
Issue-ID: DCAEGEN2-215
Signed-off-by: Snigdha Sucharita Patra <sp00503415@techmahindra.com>