Book form: can now click "start read" even when the book is marked as read

It will do the same behavior as clicking on the "read" button again to
cancel it.

front/src/BigIcon.vue

@@ -5,16 +5,13 @@ const props = defineProps({
   icon: String,
   legend: String,
   isSet: Boolean,
-  isReadonly: Boolean,
 })
 
 const hovered = ref(false)
 const isOnMobile = ref(computeIsOnMobile())
 
 const computedIcon = computed(
-  () =>
-    props.icon +
-    (!props.isReadonly && ((hovered.value && !isOnMobile.value) || props.isSet) ? 'Fill' : ''),
+  () => props.icon + ((hovered.value && !isOnMobile.value) || props.isSet ? 'Fill' : ''),
 )
 
 function computeIsOnMobile() {
@@ -34,8 +31,7 @@ onUnmounted(() => {
 
 <template>
   <div
-    class="bigiconandlegend"
-    :class="props.isReadonly ? 'widget-readonly' : 'showcanclick'"
+    class="bigiconandlegend showcanclick"
     @mouseover="hovered = true"
     @mouseout="hovered = false"
   >
@@ -79,10 +75,6 @@ onUnmounted(() => {
   padding-bottom: 30px;
 }
 
-.widget-readonly {
-  opacity: 50%;
-}
-
 @media (max-width: 1024px) {
   .bigicon {
     flex: 1;