[KLIB][tests] Reorganize "klib dump-metadata" tests

- Keep the test data under "native/native.tests/testData/klib/" dir
- Rename tests from "klib contents" to "klib dump-metadata"

native/native.tests/testData/klib/dump-metadata/builtinsSerializer/annotationArguments/enum.kt

@@ -0,0 +1,18 @@
+package test
+
+enum class Weapon {
+    ROCK,
+    PAPER,
+    SCISSORS
+}
+
+annotation class JustEnum(val weapon: Weapon)
+
+annotation class EnumArray(val enumArray: Array<Weapon>)
+
+@JustEnum(Weapon.SCISSORS)
+@EnumArray(arrayOf())
+class C1
+
+@EnumArray(arrayOf(Weapon.PAPER, Weapon.ROCK))
+class C2