[FIR] do not use FirValueParameter for function type parameter

As it is a different abstraction, introduced FirFunctionTypeParameter instead

Also, fix syntax checkers for function type parameter

^KT-55035 fixed

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/FirTreeBuilder.kt

@@ -45,6 +45,8 @@ object FirTreeBuilder : AbstractFirTreeBuilder() {
     val field by element(Declaration, variable, controlFlowGraphOwner)
     val enumEntry by element(Declaration, variable)
 
+    val functionTypeParameter by element(Other, baseFirElement)
+
     val classLikeDeclaration by sealedElement(Declaration, memberDeclaration, statement)
     val klass by sealedElement("Class", Declaration, classLikeDeclaration, statement, typeParameterRefsOwner)
     val regularClass by element(Declaration, klass, controlFlowGraphOwner)

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/NodeConfigurator.kt

@@ -411,6 +411,12 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
             needTransformOtherChildren()
         }
 
+
+        functionTypeParameter.configure {
+            +field("name", nameType, nullable = true)
+            +field("returnTypeRef", typeRef)
+        }
+
         errorProperty.configure {
             +symbol("FirErrorPropertySymbol")
         }
@@ -640,7 +646,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
 
         functionTypeRef.configure {
             +field("receiverTypeRef", typeRef, nullable = true)
-            +valueParameters
+            +fieldList("parameters", functionTypeParameter)
             +returnTypeRef
             +booleanField("isSuspend")