Fix widget dropdown title overflow

Add `block` attribute to dropdown components
to prevent long titles from overflowing dropdown headers.

Changelog: fixed

app/assets/javascripts/sidebar/components/sidebar_dropdown_widget.vue

@@ -370,6 +370,7 @@ export default {
         :loading="loading"
         class="gl-w-full"
         toggle-class="gl-max-w-100"
+        block
         @shown="setFocus"
       >
         <gl-search-box-by-type ref="search" v-model="searchTerm" />

ee/app/assets/javascripts/sidebar/components/iteration_dropdown.vue

@@ -115,7 +115,7 @@ export default {
 </script>
 
 <template>
-  <gl-dropdown :text="title" class="gl-w-full" @show="onDropdownShow">
+  <gl-dropdown :text="title" class="gl-w-full" block @show="onDropdownShow">
     <gl-dropdown-section-header class="gl-display-flex! gl-justify-content-center">{{
       __('Assign Iteration')
     }}</gl-dropdown-section-header>

ee/spec/frontend/sidebar/components/__snapshots__/iteration_dropdown_spec.js.snap

@@ -2,6 +2,7 @@
 
 exports[`IterationDropdown default shows gl-dropdown 1`] = `
 <gl-dropdown-stub
+  block="true"
   category="primary"
   class="gl-w-full"
   clearalltext="Clear all"