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>

.devcontainer/devcontainer.json

@@ -0,0 +1,35 @@
+{
+    "name": "Java",
+    "build": {
+        "dockerfile": "Dockerfile",
+        "args": {
+            // Update the VARIANT arg to pick a Java version: 8, 11, 15
+            "VARIANT": "8"
+        }
+    },
+    // Set *default* container specific settings.json values on container create.
+    "settings": {
+        "terminal.integrated.shell.linux": "/bin/bash",
+        "java.home": "/docker-java-home",
+        "java.format.settings.url": "https://raw.githubusercontent.com/eclipse/hawkbit/master/eclipse_codeformatter.xml",
+        "maven.executable.path": "/usr/local/sdkman/candidates/maven/current/bin/mvn"
+    },
+    // Add the IDs of extensions you want installed when the container is created.
+    "extensions": [
+        "vscjava.vscode-java-pack",
+        "DavidAnson.vscode-markdownlint",
+        "ms-azuretools.vscode-docker",
+        "ms-azure-devops.azure-pipelines",
+        "sonarsource.sonarlint-vscode",
+        "pivotal.vscode-spring-boot",
+        "vscjava.vscode-spring-boot-dashboard"
+    ],
+    // Use 'forwardPorts' to make a list of ports inside the container available locally.
+    "forwardPorts": [
+        8080
+    ],
+    // Use 'postCreateCommand' to run commands after the container is created.
+    // "postCreateCommand": "java -version",
+    // Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+    "remoteUser": "vscode"
+}