Add API method to get known permissions & improve the way PermissionDescriptions are migrated from existing Sponge services when LP enables

api/src/main/java/me/lucko/luckperms/api/LuckPermsApi.java

@@ -40,6 +40,9 @@ import me.lucko.luckperms.api.platform.PlatformInfo;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
+import javafx.print.Collation;
+
+import java.util.Collection;
 import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
@@ -210,6 +213,14 @@ public interface LuckPermsApi {
      */
     @NonNull ContextManager getContextManager();
 
+    /**
+     * Gets a {@link Collection} of all known permission strings.
+     *
+     * @return a collection of the known permissions
+     * @since 4.4
+     */
+    @NonNull Collection<String> getKnownPermissions();
+
     /**
      * Gets the {@link NodeFactory}.
      *