DB and RabbitMQ integration tests and PostgreSQL testing/bug fixing (#1047)

* Initial matrixSigned-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* License header

* MySQL DB testSigned-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Create matrix for DBsSigned-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* RabbitMQ and H2Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* MySQL 8.0Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Postgresql test supportSigned-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Postgresql test supportSigned-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Fix DB issues post and mssql

Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Wait MSSQL

Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Fix postgresql tests.

Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* MSSQL startup fix.Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Fix syntax error

Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Further fix postgres tests.Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Revert unnecessary changes.

Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Add SonarCloud Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

* Simplify devcontainer. Test JDK 15Signed-off-by: Kai Zimmermann <kai.zimmermann@microsoft.com>

hawkbit-repository/hawkbit-repository-test/pom.xml

@@ -51,6 +51,10 @@
       	<groupId>com.microsoft.sqlserver</groupId>
        	<artifactId>mssql-jdbc</artifactId>
       </dependency>
+      <dependency>
+		<groupId>org.postgresql</groupId>
+    	<artifactId>postgresql</artifactId>
+	  </dependency>
       <!-- Add a JDBC DB2 compatabile driver if you want to run tests against DB2, e.g. -->
 <!--       <dependency> -->
 <!--          <groupId>com.ibm.db2.jcc</groupId> -->