Fix SAT warnings (#14202)

* Fix SAT warnings

- checkstyle.ModifierOrderCheck
- checkstyle.OneStatementPerLineCheck
- checkstyle.NeedBracesCheck
- PMD.UseStandardCharsets
- PMD.UseCollectionIsEmpty
- PMD.UnusedLocalVariable
- PMD.SimplifyBooleanReturns where reasonable, suppress where
readability is better without change
- PMD.SimplifyBooleanExpressions

* Include StandardCharsets

Signed-off-by: Holger Friedrich <mail@holger-friedrich.de>

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/common/Variable.java

@@ -244,6 +244,7 @@ public enum Variable {
      * @param is2013 the target module's-generation
      * @return true if a poll is required to get the new status-value
      */
+    @SuppressWarnings("PMD.SimplifyBooleanReturns")
     public boolean shouldPollStatusAfterCommand(int firmwareVersion) {
         // Regulator set-points will send status-messages on every change (all firmware versions)
         if (type == Type.REGULATOR) {