Feature/fix sonar warnings (#1226)

* Fixed sonar warnings

- "Cognitive Complexity"
- "Do not use replaceAll when not using a regex"
- java:S5869 - Character classes in regular expressions should not contain the same character twice
- Improved bad name
- Typos
- reduced code duplications
- Replaced hand-made wait-utility with Awaitility
- Log messages
- Duplicate code
- Typos
- Removed Thread.sleep, instead relaxed check condition
- Removed use of deprecated API
- Removed use of deprecated API
- Added supress-warnings as I do not see a better way to write the tests
- Removed Thread.sleep / redundant functionality to Awaitility
- Fixed other warnings (use isZero, isEmpty, hasToString)
- Removed/Reduced duplicate code
- Added generics
- Fixed asserts
- removed: field.setAccessible(true) actually should not be needed for public static fields!
- Too long constructor passes arguments in wrong order - how surprisingly...
- Clean-up use of varargs arguments
- Fixed regex
- Fixed typos and other minor stuff
- Making public constructors protected in abstract classes
- Swapped expected and asserted argument
- volatile not enough for syncing threads
- volatile not enough for syncing threads
- out-commented code
- Made regex not-greedy, added tests for verification
- Avoid exposure of thread-local member var

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* Fixed Sonar warnings

* License header fix

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* License header fix #2

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* Fixing review findings

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* Fixing tests

- Fixed '&' usage in javadoc and typos
- Fixing some warnings

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

hawkbit-autoconfigure/src/main/java/org/eclipse/hawkbit/autoconfigure/PropertyHostnameResolverAutoConfiguration.java

@@ -22,8 +22,6 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.PropertySource;
 
-import com.google.common.base.Throwables;
-
 /**
  * Auto configuration for {@link HostnameResolver} and
  * {@link ArtifactUrlHandler} based on a properties.
@@ -46,7 +44,7 @@ public class PropertyHostnameResolverAutoConfiguration {
             try {
                 return new URL(serverProperties.getUrl());
             } catch (final MalformedURLException e) {
-                throw Throwables.propagate(e);
+                throw new IllegalArgumentException("URL not valid: " + serverProperties.getUrl(), e);
             }
         };
     }