[FIR] Remove FirLambdaArgumentExpression

It's not really necessary if the information about if the lambda was a
trailing lambda can be directly saved in FirAnonymousFunctionExpression.

Removing the FIR node uncovered a couple of bugs
(UNINITIALIZED_ENUM_ENTRY, ERROR_IN_CONTRACT_DESCRIPTION) that were
caused by assuming that a lambda is always a trailing lambda.

#KT-66124

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

@@ -143,7 +143,6 @@ object FirTreeBuilder : AbstractFirTreeBuilder() {
     val getClassCall by element(Expression, expression, call)
     val wrappedExpression by element(Expression, expression)
     val wrappedArgumentExpression by element(Expression, wrappedExpression)
-    val lambdaArgumentExpression by element(Expression, wrappedArgumentExpression)
     val spreadArgumentExpression by element(Expression, wrappedArgumentExpression)
     val namedArgumentExpression by element(Expression, wrappedArgumentExpression)
     val varargArgumentsExpression by element(Expression, expression)

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

@@ -316,16 +316,6 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
             }
         }
 
-        impl(lambdaArgumentExpression) {
-            default("isSpread") {
-                value = "false"
-                withGetter = true
-            }
-            default("coneTypeOrNull") {
-                delegate = "expression"
-            }
-        }
-
         impl(spreadArgumentExpression) {
             default("isSpread") {
                 value = "true"

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

@@ -331,6 +331,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
 
         anonymousFunctionExpression.configure {
             +field(anonymousFunction).withTransform()
+            +booleanField("isTrailingLambda", withReplace = true)
         }
 
         typeParameter.configure {