Add IN operator for fieldSelector and labelSelector (#2290)

#### What type of PR is this?

/kind feature
/kind api-change
/area core
/milestone 2.0
/release-note-none

#### What this PR does / why we need it:

- Add `IN` operator for fieldSelector and labelSelector.
- Adapt name field selector with `IN` operator.

```release-note
None
```

src/main/java/run/halo/app/extension/router/selector/FieldCriteriaPredicateConverter.java

@@ -19,7 +19,7 @@ public class FieldCriteriaPredicateConverter<E extends Extension>
                     return false;
                 }
                 switch (criteria.operator()) {
-                    case Equals -> {
+                    case Equals, IN -> {
                         return criteria.values().contains(name);
                     }
                     case NotEquals -> {

src/main/java/run/halo/app/extension/router/selector/Operator.java

@@ -6,7 +6,7 @@ import org.springframework.lang.Nullable;
 
 public enum Operator implements Converter<String, SelectorCriteria> {
 
-    Equals("=", 2) {
+    Equals("=", 3) {
         @Override
         @Nullable
         public SelectorCriteria convert(@Nullable String selector) {
@@ -21,6 +21,23 @@ public enum Operator implements Converter<String, SelectorCriteria> {
             return null;
         }
     },
+    IN("=(", 2) {
+        @Override
+        public SelectorCriteria convert(String selector) {
+            if (preFlightCheck(selector, 5)) {
+                var idx = selector.indexOf(getOperator());
+                if (idx > 0 && (idx + getOperator().length()) < selector.length() - 2
+                    && selector.charAt(selector.length() - 1) == ')') {
+                    var key = selector.substring(0, idx);
+                    var valuesString =
+                        selector.substring(idx + getOperator().length(), selector.length() - 1);
+                    String[] values = valuesString.split(",");
+                    return new SelectorCriteria(key, this, Set.of(values));
+                }
+            }
+            return null;
+        }
+    },
     NotEquals("!=", 1) {
         @Override
         @Nullable

src/test/java/run/halo/app/extension/router/selector/FieldCriteriaPredicateConverterTest.java

@@ -63,6 +63,27 @@ class FieldCriteriaPredicateConverterTest {
         assertFalse(predicate.test(fake));
     }
 
+    @Test
+    void shouldConvertNameInCorrectly() {
+        var criteria = new SelectorCriteria("name", Operator.IN, Set.of("value1", "value2"));
+        var predicate = converter.convert(criteria);
+        assertNotNull(predicate);
+
+        var fake = new FakeExtension();
+        var metadata = new Metadata();
+        fake.setMetadata(metadata);
+        assertFalse(predicate.test(fake));
+
+        metadata.setName("not-contain-value");
+        assertFalse(predicate.test(fake));
+
+        metadata.setName("value1");
+        assertTrue(predicate.test(fake));
+
+        metadata.setName("value2");
+        assertTrue(predicate.test(fake));
+    }
+
     @Test
     void shouldReturnAlwaysFalseIfCriteriaKeyNotSupported() {
         var criteria =

src/test/java/run/halo/app/extension/router/selector/OperatorTest.java

@@ -3,6 +3,7 @@ package run.halo.app.extension.router.selector;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static run.halo.app.extension.router.selector.Operator.Equals;
 import static run.halo.app.extension.router.selector.Operator.Exist;
+import static run.halo.app.extension.router.selector.Operator.IN;
 import static run.halo.app.extension.router.selector.Operator.NotEquals;
 import static run.halo.app.extension.router.selector.Operator.NotExist;
 
@@ -46,7 +47,13 @@ class OperatorTest {
             new TestCase("name", Exist, new SelectorCriteria("name", Exist, Set.of())),
             new TestCase("", Exist, null),
             new TestCase("!", Exist, new SelectorCriteria("!", Exist, Set.of())),
-            new TestCase("a", Exist, new SelectorCriteria("a", Exist, Set.of()))
+            new TestCase("a", Exist, new SelectorCriteria("a", Exist, Set.of())),
+
+            new TestCase("name", IN, null),
+            new TestCase("name=(fake-name)", IN,
+                new SelectorCriteria("name", IN, Set.of("fake-name"))),
+            new TestCase("name=(first-name,second-name)", IN,
+                new SelectorCriteria("name", IN, Set.of("first-name", "second-name")))
         ).forEach(testCase -> {
             log.debug("Testing: {}", testCase);
             assertEquals(testCase.expected(), testCase.converter().convert(testCase.source()));