Check componentN functions for override conflicts

Check if newly generated component functions happen to override something
which they're not supposed to.
Create new slice to store mapping from annotation descriptors to
corresponding PSI elements, which is used by override checker to report
errors in data classes on.

compiler/testData/diagnostics/tests/dataClasses/implementTraitWhichHasFinalComponent1.kt

@@ -0,0 +1,5 @@
+trait T {
+    final fun component1(): Int = 42
+}
+
+<!DATA_CLASS_OVERRIDE_CONFLICT!>data<!> class A(val x: Int) : T