refactor: support for custom api group in plugin controllers (#4065)

#### What type of PR is this?
/kind improvement
/area core
/milestone 2.7.x

#### What this PR does / why we need it:
插件的 Controllers 支持自定义 API Group
如：
```java
@RestController
@ApiVersion("fake.halo.run/v1")
@RequestMapping("/fake")
public class DemoController {
}
```
则生成路由为 `/apis/fake.halo.run/v1/fake`
如果没有 group 默认兼容以前的为 `/apis/api.plugin.halo.run/{version}/plugins/{pluginName}/**`
```java
@RestController
@ApiVersion("v1alpha1")
@RequestMapping("/fake")
public class DemoController {
}
```

#### Which issue(s) this PR fixes:
Fixes #4053

#### Does this PR introduce a user-facing change?
```release-note
插件的 Controllers 支持自定义 API Group
```

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

@@ -7,7 +7,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
 import java.util.stream.Collectors;
-import org.pf4j.PluginRuntimeException;
 import org.springframework.aop.support.AopUtils;
 import org.springframework.core.MethodIntrospector;
 import org.springframework.stereotype.Controller;
@@ -117,8 +116,7 @@ public class PluginRequestMappingHandlerMapping extends RequestMappingHandlerMap
         if (info != null) {
             ApiVersion apiVersion = handlerType.getAnnotation(ApiVersion.class);
             if (apiVersion == null) {
-                throw new PluginRuntimeException(
-                    "The handler [" + handlerType + "] is missing @ApiVersion annotation.");
+                return info;
             }
             info = RequestMappingInfo.paths(buildPrefix(pluginId, apiVersion.value())).build()
                 .combine(info);
@@ -126,9 +124,14 @@ public class PluginRequestMappingHandlerMapping extends RequestMappingHandlerMap
         return info;
     }
 
-    protected String buildPrefix(String pluginId, String version) {
-        GroupVersion groupVersion = GroupVersion.parseAPIVersion(version);
+    protected String buildPrefix(String pluginName, String apiVersion) {
+        GroupVersion groupVersion = GroupVersion.parseAPIVersion(apiVersion);
+        if (StringUtils.hasText(groupVersion.group())) {
+            // apis/{group}/{version}
+            return String.format("/apis/%s/%s", groupVersion.group(), groupVersion.version());
+        }
+        // apis/api.plugin.halo.run/{version}/plugins/{pluginName}
         return String.format("/apis/api.plugin.halo.run/%s/plugins/%s", groupVersion.version(),
-            pluginId);
+            pluginName);
     }
 }

application/src/test/java/run/halo/app/plugin/PluginRequestMappingHandlerMappingTest.java

@@ -1,7 +1,6 @@
 package run.halo.app.plugin;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.Mockito.mock;
 import static org.springframework.mock.http.server.reactive.MockServerHttpRequest.get;
 import static org.springframework.mock.http.server.reactive.MockServerHttpRequest.post;
@@ -20,7 +19,6 @@ import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.pf4j.PluginRuntimeException;
 import org.springframework.core.MethodIntrospector;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.http.HttpMethod;
@@ -74,15 +72,14 @@ class PluginRequestMappingHandlerMappingTest {
     }
 
     @Test
-    public void shouldFailWhenMissingApiVersion() throws Exception {
+    public void shouldKeepRawWhenMissingApiVersion() throws Exception {
         Method method = AppleMissingApiVersionController.class.getMethod("getName");
-        assertThatThrownBy(() ->
+        RequestMappingInfo info =
             this.handlerMapping.getPluginMappingForMethod("fakePlugin", method,
-                AppleMissingApiVersionController.class)).isInstanceOf(PluginRuntimeException.class)
-            .hasMessage(
-                "The handler [class run.halo.app.plugin"
-                    + ".PluginRequestMappingHandlerMappingTest$AppleMissingApiVersionController] "
-                    + "is missing @ApiVersion annotation.");
+                AppleMissingApiVersionController.class);
+
+        assertThat(info.getPatternsCondition().getPatterns())
+            .isEqualTo(Collections.singleton(new PathPatternParser().parse("/apples")));
     }
 
     @Test
@@ -174,6 +171,15 @@ class PluginRequestMappingHandlerMappingTest {
                 Set.of(HttpMethod.GET, HttpMethod.HEAD)));
     }
 
+    @Test
+    void buildPrefix() {
+        String s = handlerMapping.buildPrefix("fakePlugin", "v1");
+        assertThat(s).isEqualTo("/apis/api.plugin.halo.run/v1/plugins/fakePlugin");
+
+        s = handlerMapping.buildPrefix("fakePlugin", "fake.halo.run/v1alpha1");
+        assertThat(s).isEqualTo("/apis/fake.halo.run/v1alpha1");
+    }
+
     @SuppressWarnings("unchecked")
     private <T> void assertError(Mono<Object> mono, final Class<T> exceptionClass,
         final Consumer<T> consumer) {