Introduce importmap, enhance elimination workflows, and update assets

This commit adds initial importmap configuration to manage assets, updates the elimination preparation workflow with form enhancements and database changes, introduces new styles and JS assets, refines translations, and improves entity handling with an input bag update method.

templates/backoffice/prepare_elimination/index.html.twig

@@ -17,7 +17,7 @@
     </div>
     <div class="row">
         <div class="col-12 col-md-6">
-            <form>
+            <form method="post">
                 {%~ for candidate, colour in elimination.data %}
                     <div class="row mb-3">
                         <label for="colour-{{ candidate|lower }}" class="col-4 col-form-label">{{ candidate }}</label>
@@ -30,7 +30,13 @@
                         </div>
                     </div>
                 {% endfor %}
-                <button type="submit" class="btn btn-primary">{{ 'Save'|trans }}</button>
+                <div class="btn-group py-2">
+                    <button type="submit" class="btn btn-primary" name="start" value="1">{{ 'Save'|trans }}</button>
+                    <button type="submit" class="btn btn-success" name="start"
+                            value="0">{{ 'Save and start elimination'|trans }}</button>
+                    <a href="{{ path('app_backoffice_quiz', {seasonCode: elimination.quiz.season.seasonCode, quiz: elimination.quiz.id}) }}"
+                       class="btn btn-secondary">{{ 'Back'|trans }}</a>
+                </div>
             </form>
         </div>
         <div class="col-12 col-md-6">