Remove all client-side validation and rely on server-side validation

Gives better error messages to the user.

view/src/main/java/se/su/dsv/scipro/match/IdeaTholanderCompletionPanel.java

@@ -22,15 +22,7 @@ public class IdeaTholanderCompletionPanel extends Panel {
 
     private void textField(String id, IModel<String> model) {
         TextArea<String> textArea = new TextArea<>(id, model);
-        textArea.add(
-            new StringValidator(null, TholanderBox.MAX_CHARS) {
-                @Override
-                protected boolean hasLengthAttribute(String tagName) {
-                    // remove the maxlength attribute from the tag to disable client side validation
-                    return false;
-                }
-            }
-        );
+        textArea.add(StringValidator.maximumLength(TholanderBox.MAX_CHARS));
         textArea.setRequired(true);
         add(textArea);
 

view/src/main/java/se/su/dsv/scipro/match/ProjectIdeaSubmissionPanel.html

@@ -17,7 +17,14 @@
         an idea if you couldn't find any suitable supervisor provided ideas.
     </div>
 
-    <form wicket:id="ideaForm">
+    <!--
+        Turn off all client-side validation using novalidate.
+        All input is validated server-side, and we want to validate it
+        that way to get nice error messages.
+        However, we also want to maintain the required/minlength/whatever
+        attributes on the input fields for accessibility.
+     -->
+    <form wicket:id="ideaForm" novalidate>
         <div class="mb-3">
             <label class="col-form-label" wicket:for="title">Title</label>
             <p class="form-text">

view/src/main/java/se/su/dsv/scipro/match/ProjectIdeaSubmissionPanel.java

@@ -307,15 +307,7 @@ public class ProjectIdeaSubmissionPanel extends GenericPanel<Idea> {
                 LambdaModel.of(getModel(), Idea::getTitle, Idea::setTitle)
             );
             title.setRequired(true);
-            title.add(
-                new StringValidator(MIN_TITLE_LENGTH, null) {
-                    @Override
-                    protected boolean hasLengthAttribute(String tagName) {
-                        // remove the minlength attribute from the tag to disable client side validation
-                        return false;
-                    }
-                }
-            );
+            title.add(StringValidator.minimumLength(MIN_TITLE_LENGTH));
             add(new ComponentFeedbackPanel("titleFeedback", title));
             add(title);
         }