refactor(core): migrate to standard Java ServiceLoader for plugins

Changes:
- add new top level interface `Plugin`
- add new `JsonDeserializer` aware of the `PluginRegistry`
- add new annotation processor for plugin
- migrate to hibernate-validator for the JSR-303 (no bean introspection dependencies)
- update all Validation annotations to be complitant with the JSR-303
- remove all KestraApplicationContext stuffs
- fix some tests

part-of: kestra-io/plugin-template-test#25
part-of: kestra-io/plugin-serdes#103

storage-local/build.gradle

@@ -1,5 +1,7 @@
 dependencies {
+    annotationProcessor project(":processor")
     implementation project(":core")
 
+    testAnnotationProcessor project(":processor")
     testImplementation project(':core').sourceSets.test.output
 }

storage-local/src/main/java/io/kestra/storage/local/LocalStorage.java

@@ -1,5 +1,6 @@
 package io.kestra.storage.local;
 
+import io.kestra.core.models.annotations.Plugin;
 import io.kestra.core.storages.FileAttributes;
 import io.kestra.core.storages.StorageInterface;
 import jakarta.inject.Inject;
@@ -18,11 +19,17 @@ import java.util.stream.Stream;
 
 import static io.kestra.core.utils.Rethrow.throwFunction;
 
+@Plugin
 @Singleton
 @LocalStorageEnabled
 public class LocalStorage implements StorageInterface {
     LocalConfig config;
 
+    /**
+     * No-arg constructor - required by Kestra service loader.
+     */
+    public LocalStorage() {}
+    
     @Inject
     public LocalStorage(LocalConfig config) throws IOException {
         this.config = config;