refactor: Update label generation in Defaultable.scala and Form.scala

This commit refactors the label generation in Defaultable.scala and Form.scala to use the NameUtils.titleCase function. This function converts a string to title case, which is used to generate more readable labels for types and parameters.

The changes in Defaultable.scala update the label generation for the type to use the titleCase function on the class name. This improves the readability of the label.

In Form.scala, the label generation for parameters without a FieldName annotation is also updated to use the titleCase function. This ensures consistent and more readable labels for form fields.

A new utility class, NameUtils, is added to the project. This class provides the titleCase function, which splits a string into words and capitalizes the first letter of each word. This function is used in the label generation changes.

These changes improve the clarity and readability of the codebase.

modules/core/src/main/scala/dev/cheleb/scalamigen/Defaultable.scala

@@ -20,7 +20,8 @@ trait Defaultable[A] {
 
   /** The label for the type.
     */
-  def label: String = default.getClass.getSimpleName()
+  def label: String =
+    NameUtils.titleCase(default.getClass.getSimpleName)
 }
 
 object Defaultable {

modules/core/src/main/scala/dev/cheleb/scalamigen/Form.scala

@@ -538,7 +538,7 @@ object Form extends AutoDerivation[Form] {
 
             val fieldName = param.annotations
               .find(_.isInstanceOf[FieldName]) match
-              case None => titleCase(param.label)
+              case None => NameUtils.titleCase(param.label)
               case Some(value) =>
                 value.asInstanceOf[FieldName].value
             tr(
@@ -580,7 +580,7 @@ object Form extends AutoDerivation[Form] {
 
           val fieldName = param.annotations
             .find(_.isInstanceOf[FieldName]) match
-            case None => titleCase(param.label)
+            case None => NameUtils.titleCase(param.label)
             case Some(value) =>
               value.asInstanceOf[FieldName].value
 
@@ -648,11 +648,6 @@ object Form extends AutoDerivation[Form] {
   def getSubtypeLabel[T](sub: Subtype[Typeclass, T, ?]): String =
     sub.annotations
       .collectFirst { case label: FieldName => label.value }
-      .getOrElse(titleCase(sub.typeInfo.short))
-
-  /** someParameterName -> Some Parameter Name camelCase -> Title Case
-    */
-  private def titleCase(string: String): String =
-    string.split("(?=[A-Z])").map(_.capitalize).mkString(" ")
+      .getOrElse(NameUtils.titleCase(sub.typeInfo.short))
 
 }

modules/core/src/main/scala/dev/cheleb/scalamigen/NameUtils.scala

@@ -0,0 +1,13 @@
+package dev.cheleb.scalamigen
+
+object NameUtils {
+
+  /** someParameterName -> Some Parameter Name camelCase -> Title Case
+    */
+  def titleCase(string: String): String =
+    string
+      .filter(_.isLetter)
+      .split("(?=[A-Z])")
+      .map(_.capitalize)
+      .mkString(" ")
+}