[FIR] Don't create backing field for property without explicit type

#KT-41977 Fixed

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/explicitGetterType.fir.kt

@@ -5,7 +5,7 @@ val z get(): List<Int> {
     return bar()
 }
 
-val u get(): String = field
+val u get(): String = <!UNRESOLVED_REFERENCE!>field<!>
 
 fun <E> foo(): E = null!!
 fun <E> bar(): List<E> = null!!

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/recursiveGetter.fir.kt

@@ -13,7 +13,7 @@ class A {
     val z1 get() = <!INAPPLICABLE_CANDIDATE!>id<!>(z1)
     val z2 get() = <!INAPPLICABLE_CANDIDATE!>l<!>(z2)
 
-    val u get() = field
+    val u get() = <!UNRESOLVED_REFERENCE!>field<!>
 }
 
 fun <E> id(x: E) = x

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/unsupportedInferenceFromGetters.fir.kt

@@ -21,7 +21,7 @@ val z2 get(): List<Int> {
     return bar()
 }
 
-val u get(): String = field
+val u get(): String = <!UNRESOLVED_REFERENCE!>field<!>
 
 // members.kt
 class A {
@@ -68,4 +68,4 @@ object Outer {
         set(q) {
             x = q
         }
-}
+}