[MercedesMe] Switch to Mercedes App SDK (openhab#15628)

* add protocol buffer definitions
* oauth rework
* websocket introduction

Signed-off-by: Bernd Weymann <[email protected]>
Signed-off-by: Ciprian Pascu <[email protected]>

Author: weymann

bundles/org.openhab.binding.mercedesme/README.md

@@ -10,6 +10,28 @@
     <version>4.2.0-SNAPSHOT</version>
   </parent>
 
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>build-helper-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <goals>
+              <goal>add-source</goal>
+            </goals>
+            <phase>generate-sources</phase>
+            <configuration>
+              <sources>
+                <source>src/3rdparty/java</source>
+              </sources>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+
   <dependencies>
     <!-- version needs to match with other projects like org.openhab.io.openhabcloud.pom.xml -->
     <dependency>
@@ -18,6 +40,13 @@
       <version>20231013</version>
       <scope>compile</scope>
     </dependency>
+    <!-- https://mvnrepository.com/artifact/com.google.protobuf/protobuf-java -->
+    <dependency>
+      <groupId>com.google.protobuf</groupId>
+      <artifactId>protobuf-java</artifactId>
+      <version>4.26.1</version>
+      <scope>compile</scope>
+    </dependency>
   </dependencies>
 
   <artifactId>org.openhab.binding.mercedesme</artifactId>

bundles/org.openhab.binding.mercedesme/doc/CallbackUrl_Page.png

@@ -0,0 +1,7 @@
+# How to protoc
+
+- Check [mvn repository](https://mvnrepository.com/artifact/com.google.protobuf/protobuf-java-util) which version to use 
+- Download correct protoc compiler from [maven central](https://repo1.maven.org/maven2/com/google/protobuf/protoc/) into `PROTOC_DIR`
+- Call in mercedesme binding directory `PROTOC_DIR\protoc -I=proto --java_out=gen proto/*.proto`
+- Move generated sources including subdirs from `gen` to `3rdparty\java`
+- Adapt `pom.xml` with version of step 1