Multisrc bugfix and genkan refactor (#5707)

* themesource bugfix, refactor genkan

* revert 3da46570aa

annotations/build.gradle.kts

@@ -0,0 +1,7 @@
+plugins {
+    id("kotlin")
+}
+
+dependencies {
+    compileOnly(Deps.kotlin.stdlib)
+}

annotations/src/main/kotlin/Nsfw.kt

@@ -0,0 +1,10 @@
+package eu.kanade.tachiyomi.annotations
+
+/**
+ * Annotation used to mark a Source (i.e. individual sources) or a SourceFactory (i.e. all sources
+ * within it) as NSFW. Used within the Tachiyomi app to prevent loading sources when parental
+ * controls are enabled.
+ */
+@Retention(AnnotationRetention.RUNTIME)
+@Target(AnnotationTarget.CLASS)
+annotation class Nsfw