refactor: plugin resource loading to only load from plugin itself instead of delegating to core (#4663)

#### What type of PR is this?
/kind improvement
/area core
/area plugin
/milestone 2.10.x

#### What this PR does / why we need it:
重构插件类加载器以优化当插件的 resources 目录资源与 Halo 中同名时加载不到的问题

how to test it?
1. 在创建的 resources/extensions 目录创建一个与 halo 的 resources/extensions 目录中已存在的同名 yaml
2. 使用插件观察插件的同名文件 yaml 是否被 apply 到 halo 中
3. 测试插件的其他功能是否正常比如静态资源加载如 logo 等

#### Which issue(s) this PR fixes:
Fixes #4610

#### Does this PR introduce a user-facing change?
```release-note
重构插件类加载器以优化当插件的 resources 目录资源与 Halo 中同名时加载不到的问题
```

application/src/main/java/run/halo/app/plugin/PluginAutoConfiguration.java

@@ -10,14 +10,12 @@ import java.nio.file.Path;
 import java.time.Instant;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
-import org.pf4j.ClassLoadingStrategy;
 import org.pf4j.CompoundPluginLoader;
 import org.pf4j.CompoundPluginRepository;
 import org.pf4j.DefaultPluginRepository;
 import org.pf4j.DevelopmentPluginLoader;
 import org.pf4j.JarPluginLoader;
 import org.pf4j.JarPluginRepository;
-import org.pf4j.PluginClassLoader;
 import org.pf4j.PluginDescriptor;
 import org.pf4j.PluginLoader;
 import org.pf4j.PluginManager;
@@ -111,17 +109,7 @@ public class PluginAutoConfiguration {
                     } else {
                         return new CompoundPluginLoader()
                             .add(createDevelopmentPluginLoader(this), this::isDevelopment)
-                            .add(new JarPluginLoader(this) {
-                                @Override
-                                public ClassLoader loadPlugin(Path pluginPath,
-                                    PluginDescriptor pluginDescriptor) {
-                                    PluginClassLoader pluginClassLoader =
-                                        new PluginClassLoader(pluginManager, pluginDescriptor,
-                                            getClass().getClassLoader(), ClassLoadingStrategy.APD);
-                                    pluginClassLoader.addFile(pluginPath.toFile());
-                                    return pluginClassLoader;
-                                }
-                            });
+                            .add(new JarPluginLoader(this));
                     }
                 }
 
@@ -156,12 +144,6 @@ public class PluginAutoConfiguration {
 
     DevelopmentPluginLoader createDevelopmentPluginLoader(PluginManager pluginManager) {
         return new DevelopmentPluginLoader(pluginManager) {
-            @Override
-            protected PluginClassLoader createPluginClassLoader(Path pluginPath,
-                PluginDescriptor pluginDescriptor) {
-                return new PluginClassLoader(pluginManager, pluginDescriptor,
-                    getClass().getClassLoader(), ClassLoadingStrategy.APD);
-            }
 
             @Override
             public ClassLoader loadPlugin(Path pluginPath,