FIR IDE: move analysis api fir testdata to the analysis directory

analysis/analysis-api/testData/fileScopeTest/simpleFileScope.kt

@@ -0,0 +1,11 @@
+fun test(): Int = 3
+
+val testVal: Int = 2
+
+class C {
+    fun r() {
+
+    }
+}
+
+interface I