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

analysis/analysis-api/testData/components/importOptimizer/unusedFunctionImports.kt

@@ -0,0 +1,14 @@
+// FILE: main.kt
+package test
+
+import dependency.foo
+import dependency.bar
+
+fun usage() {}
+
+// FILE: dependency.kt
+package dependency
+
+fun foo() {}
+
+fun bar() {}