[FIR] add support for implementation by delgation

This commit handles "subclass: super-interface by delegate-expression".

During Psi2Fir, for each delegate, we add to the subclass a synthetic
field (which has type super-interface), and an assignment of the
delegate-expression to the synthetic field in the primary constructor,
so that the delegate-expression can be resolved and transformed along
the way.

During Fir2Ir, we look up delegatable members from the super-interface
and generate corresponding functions/properties for the subclass.

TODO: support for generic delegatable members and generic
super-interface.

compiler/fir/analysis-tests/testData/resolve/delegatedSuperType.txt

@@ -13,8 +13,11 @@ FILE: delegatedSuperType.kt
 
     }
     public final class C : R|A| {
+        local final field $$delegate_0: R|A|
+
         public constructor(b: R|B|): R|C| {
             super<R|kotlin/Any|>()
+            this@R|/C|.R|<local>/$$delegate_0| = R|<local>/b|
         }
 
         public final val b: R|B| = R|<local>/b|