[openwebnet] fixing support for central unit (#12514)

* - read Temperature set in central unit at startup
* - ignoring what 4002 which may lead to unpredicted behaviours
- usage of own 0.8.0 from mvalla (new getWhatParameter method)
* attempt to integrate own 0.8.0
* - read setTemp (MANUAL mode) at startup
- read mode (OFF/PROTECTION/WEEKLY/SCENARIO/MANUAL) at startup
- persist selected mode (see issue 12401)
* remove unnecessary logs
* - fix typo
- own4j 0.8.1
* fix placeholder count

Signed-off-by: Conte Andrea <andrea@conte.com>

bundles/org.openhab.binding.openwebnet/pom.xml

@@ -23,7 +23,7 @@
     <dependency>
       <groupId>io.github.openwebnet4j</groupId>
       <artifactId>openwebnet4j</artifactId>
-      <version>0.7.1</version>
+      <version>0.8.1</version>
       <scope>compile</scope>
     </dependency>