FIR: introduce delegated & overridden conflict checks

compiler/testData/diagnostics/tests/delegation/covariantOverrides/fromClass.fir.kt

@@ -6,7 +6,7 @@ open class IDerived1 : IBase1 {
     override fun foo(): String = "1"
 }
 
-class Broken1(val b: IBase1) : IBase1 by b, IDerived1()
+<!DELEGATED_MEMBER_HIDES_SUPERTYPE_OVERRIDE!>class Broken1<!>(val b: IBase1) : IBase1 by b, IDerived1()
 
 interface IBase2 {
     val foo: Any
@@ -16,4 +16,4 @@ open class IDerived2 : IBase2 {
     override val foo: String = "2"
 }
 
-class Broken2(val b: IBase2) : IBase2 by b, IDerived2()
+<!DELEGATED_MEMBER_HIDES_SUPERTYPE_OVERRIDE!>class Broken2<!>(val b: IBase2) : IBase2 by b, IDerived2()