add support of UIKitInverse and UIKitOverlay

src/jsMain/kotlin/dev/inmo/jsuikit/modifiers/UIKitInverse.kt

@@ -0,0 +1,8 @@
+package dev.inmo.jsuikit.modifiers
+
+sealed class UIKitInverse(classname: String) : UIKitModifier {
+    override val classes: Array<String> = arrayOf(classname)
+
+    object Light : UIKitInverse("uk-light")
+    object Dark : UIKitInverse("uk-dark")
+}

src/jsMain/kotlin/dev/inmo/jsuikit/modifiers/UIKitOverlay.kt

@@ -0,0 +1,16 @@
+package dev.inmo.jsuikit.modifiers
+
+sealed class UIKitOverlay(
+    override val classes: Array<String> = emptyArray(),
+    override val otherAttrs: Map<String, String> = emptyMap()
+) : UIKitModifier {
+
+    object Default : UIKitOverlay(arrayOf("uk-overlay-default"))
+    object Primary : UIKitOverlay(arrayOf("uk-overlay-primary"))
+    object Icon : UIKitOverlay(arrayOf("uk-overlay-icon"))
+
+    companion object : UIKitOverlay(
+        arrayOf("uk-overlay")
+    )
+
+}