Rename ide-radio-label to ide-option-label

**Why?**
We now use it in a checkbox :)

app/assets/javascripts/ide/components/commit_sidebar/actions.vue

@@ -70,7 +70,7 @@ export default {
       :title="$options.currentBranchPermissionsTooltip"
     >
       <span
-        class="ide-radio-label"
+        class="ide-option-label"
         data-qa-selector="commit_to_current_branch_radio"
         v-html="commitToCurrentBranchText"
       ></span>

app/assets/javascripts/ide/components/commit_sidebar/new_merge_request_option.vue

@@ -44,7 +44,7 @@ export default {
         data-qa-selector="start_new_mr_checkbox"
         @change="toggleShouldCreateMR"
       />
-      <span class="prepend-left-10 ide-radio-label">
+      <span class="prepend-left-10 ide-option-label">
         {{ __('Start a new merge request') }}
       </span>
     </label>

app/assets/javascripts/ide/components/commit_sidebar/radio_group.vue

@@ -67,7 +67,7 @@ export default {
         @change="updateCommitAction($event.target.value)"
       />
       <span class="prepend-left-10">
-        <span v-if="label" class="ide-radio-label"> {{ label }} </span> <slot v-else></slot>
+        <span v-if="label" class="ide-option-label"> {{ label }} </span> <slot v-else></slot>
       </span>
     </label>
     <div v-if="commitAction === value && showInput" class="ide-commit-new-branch">

app/assets/stylesheets/page_bundles/ide.scss

@@ -688,7 +688,7 @@ $ide-commit-header-height: 48px;
     font-weight: normal;
 
     &.is-disabled {
-      .ide-radio-label {
+      .ide-option-label {
         text-decoration: line-through;
       }
     }