[FIR & IR] Support of default values for arguments in expect functions

Add FirActualDeclarationChecker that checks expect/actual return types

^KT-56331 Fixed, ^KT-56334 Fixed

compiler/testData/diagnostics/tests/multiplatform/defaultArguments/expectedVsNonExpectedWithDefaults.fir.kt

@@ -1,16 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-// MODULE: m1-common
-// FILE: common.kt
-
-expect fun ok(x: Int, y: String = "")
-
-// MODULE: m2-jvm()()(m1-common)
-// FILE: jvm.kt
-
-actual fun ok(x: Int, y: String) {}
-
-fun ok(x: Int, y: Long = 1L) {}
-
-fun test() {
-    ok(1)
-}

compiler/testData/diagnostics/tests/multiplatform/defaultArguments/expectedVsNonExpectedWithDefaults.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 // MODULE: m1-common
 // FILE: common.kt