feat: FollowとAcceptのclassを追加

src/main/kotlin/dev/usbharu/hideout/ap/Accept.kt

@@ -0,0 +1,16 @@
+package dev.usbharu.hideout.ap
+
+open class Accept : Object {
+    public var `object`:Object? = null
+    public var actor:String? = null
+    protected constructor() : super()
+    constructor(
+        type: List<String> = emptyList(),
+        name: String,
+        `object`: Object?,
+        actor: String?
+    ) : super(add(type,"Accept"), name) {
+        this.`object` = `object`
+        this.actor = actor
+    }
+}

src/main/kotlin/dev/usbharu/hideout/ap/Follow.kt

@@ -0,0 +1,16 @@
+package dev.usbharu.hideout.ap
+
+open class Follow : Object{
+    public var `object`:Object? = null
+    public var actor:String? = null
+    protected constructor() : super()
+    constructor(
+        type: List<String> = emptyList(),
+        name: String,
+        `object`: Object?,
+        actor: String?
+    ) : super(add(type,"Follow"), name) {
+        this.`object` = `object`
+        this.actor = actor
+    }
+}

src/main/kotlin/dev/usbharu/hideout/service/ActivityPubService.kt

@@ -15,7 +15,7 @@ class ActivityPubService() {
         return when(typeAsText){
             "Follow" -> ActivityType.Follow
             "Undo" -> ActivityType.Undo
-            else -> throw IllegalArgumentException()
+            else -> throw IllegalArgumentException(typeAsText)
         }
     }
 }