Add zero terminator to native interop strings (#333)

skiko/src/nativeMain/kotlin/org/jetbrains/skia/impl/Native.native.kt

@@ -58,7 +58,9 @@ actual class InteropScope actual constructor() {
     actual fun toInterop(string: String?): InteropPointer {
         return if (string != null) {
             // encodeToByteArray encodes to utf8
-            val pinned = string.encodeToByteArray().pin()
+            val utf8 = string.encodeToByteArray()
+            // TODO Remove array copy, use `skString(data, length)` instead of `skString(data)`
+            val pinned = utf8.copyOf(utf8.size + 1).pin()
             elements.add(pinned)
             val result = pinned.addressOf(0).rawValue
             result