FIR IDE: move low level api testdata sources to the analysis directory

analysis/low-level-api-fir/testdata/fileStructure/declarationsInPropertyInit.kt

@@ -0,0 +1,11 @@
+class A {/* NonReanalyzableDeclarationStructureElement */
+    val a = run {
+        class X()
+
+        val y = 10
+    }/* NonReanalyzableDeclarationStructureElement */
+}
+
+inline fun <R> run(block: () -> R): R {/* ReanalyzableFunctionStructureElement */
+    return block()
+}