Set correct IR origins for inc/dec operations

NB: in order to produce correct IR origins, the source element kinds for
some FIR elements has been changed. As a side effect, mapping PSI to FIR
slightly changed: namely, for `a[b]++`, `a[b]` used to be mapped on
`set` call or callable reference, but now it is mapped on `get` call.

^KT-61891: Fixed
^KT-64387: Fixed

analysis/analysis-api/testData/referenceResolve/arrayAccess/SetOperatorInc.txt

@@ -1,2 +1,2 @@
 Resolved to:
-0: (in test.B) operator fun set(i: kotlin.Int, a: test.B)
+0: (in test.B) operator fun get(i: kotlin.Int): test.B