[FIR/IR generator] Commonize visitor printing logic

This is a step towards commonizing the code generator between
FIR and IR: KT-61970

Also, don't use kotlinpoet for generating IR visitors (KT-61703)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirDefaultVisitor.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.fir.references.*
 import org.jetbrains.kotlin.fir.types.*
 
 abstract class FirDefaultVisitor<out R, in D> : FirVisitor<R, D>() {
+
     override fun visitTypeRef(typeRef: FirTypeRef, data: D): R = visitAnnotationContainer(typeRef, data)
 
     override fun visitResolvedDeclarationStatus(resolvedDeclarationStatus: FirResolvedDeclarationStatus, data: D): R = visitDeclarationStatus(resolvedDeclarationStatus, data)
@@ -188,5 +189,4 @@ abstract class FirDefaultVisitor<out R, in D> : FirVisitor<R, D>() {
     override fun visitRawContractDescription(rawContractDescription: FirRawContractDescription, data: D): R = visitContractDescription(rawContractDescription, data)
 
     override fun visitResolvedContractDescription(resolvedContractDescription: FirResolvedContractDescription, data: D): R = visitContractDescription(resolvedContractDescription, data)
-
 }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirVisitor.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.references.*
 import org.jetbrains.kotlin.fir.types.*
 
 abstract class FirVisitor<out R, in D> {
+
     abstract fun visitElement(element: FirElement, data: D): R
 
     open fun visitAnnotationContainer(annotationContainer: FirAnnotationContainer, data: D): R = visitElement(annotationContainer, data)
@@ -328,5 +329,4 @@ abstract class FirVisitor<out R, in D> {
     open fun visitRawContractDescription(rawContractDescription: FirRawContractDescription, data: D): R = visitElement(rawContractDescription, data)
 
     open fun visitResolvedContractDescription(resolvedContractDescription: FirResolvedContractDescription, data: D): R = visitElement(resolvedContractDescription, data)
-
 }