UNOMI-856: return all rules when calling /rules endpoints (#707)

* UNOMI-856: return all rules when calling /rules endpoints

* UNOMI-856: add javadoc

api/src/main/java/org/apache/unomi/api/services/RulesService.java

@@ -37,7 +37,7 @@ public interface RulesService {
 
     /**
      * Retrieves the metadata for all known rules.
-     *
+     * Note that it only includes the rules in memory, not those persisted in storage.
      * @return the Set of known metadata
      */
     Set<Metadata> getRuleMetadatas();

rest/src/main/java/org/apache/unomi/rest/endpoints/RulesServiceEndPoint.java

@@ -66,7 +66,7 @@ public void setRulesService(RulesService rulesService) {
 
     /**
      * Retrieves the metadata for all known rules.
-     *
+     * Note that it only includes the rules in memory, not those persisted in storage.
      * @return the Set of known metadata
      */
     @GET

services/src/main/java/org/apache/unomi/services/impl/rules/RulesServiceImpl.java

@@ -355,7 +355,7 @@ public void resetAllRuleStatistics() {
 
     public Set<Metadata> getRuleMetadatas() {
         Set<Metadata> metadatas = new HashSet<Metadata>();
-        for (Rule rule : persistenceService.getAllItems(Rule.class, 0, 50, null).getList()) {
+        for (Rule rule : allRules) {
             metadatas.add(rule.getMetadata());
         }
         return metadatas;