FIR: check assignments and references to members in constructors

I.e. emit VAL_REASSIGNMENT on repeated assignments to `this.something`,
UNINITIALIZED_VARIABLE on reads of it before any assignment if there is
no initializer, and CAPTURED_MEMBER_VAL_INITIALIZATION on assignments
inside non-called-in-place functions and named classes.

^KT-55528 Fixed

compiler/testData/diagnostics/testsWithStdLib/contracts/controlflow/initialization/exactlyOnce/valDefiniteInitialization.fir.kt

@@ -87,7 +87,7 @@ class DefiniteInitializationInInitSection {
 
     init {
         myRun { x = 42 }
-        unknownRun { y = 239 }
+        unknownRun { <!CAPTURED_MEMBER_VAL_INITIALIZATION!>y<!> = 239 }
     }
 }