KT-50728 Enforce receiver type resolve

When stdlib is represented as a source dependency (which seems to be the
case in the `kotlin` project), it will be resolved lazily for the IDE.
Same thing can happen if someone decides to "extend" the stdlib
by declaring their declaration in the `kotlin` package

In both of those cases, we need to make sure that receiver type is fully
resolved before trying to get a `coneType` from it

N.B. To make resolve tests work, I've added a separate folder
`withAllowedKotlinPackage` to the `testData`, because in the default
test setup it is not allowed to extend the `kotlin` package by user's
definitions

^KT-50728 Fixed

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevels.kt

@@ -262,7 +262,7 @@ class ScopeTowerLevel(
         if (scope is FirDefaultStarImportingScope && extensionReceiver != null) {
             val extensionReceiverType = extensionReceiver.type
             if (extensionReceiverType is ConeClassLikeType) {
-                val declarationReceiverType = candidate.fir.receiverTypeRef?.coneType
+                val declarationReceiverType = candidate.resolvedReceiverTypeRef?.coneType
                 if (declarationReceiverType is ConeClassLikeType) {
                     if (!AbstractTypeChecker.isSubtypeOf(
                             session.typeContext,