[gui] Use textarea at source component description

The `Description` field on the Web GUI when editing source components
is a single-line textbox, which makes writing anything longer than six
words needing scroll. For this reason we turn the UI element into a
textarea.

web/server/vue-cli/src/components/Report/SourceComponent/EditSourceComponentDialog.vue

@@ -56,7 +56,7 @@
               :rules="rules.value"
             />
 
-            <v-text-field
+            <v-textarea
               v-model.trim="component.description"
               class="component-description "
               label="Description"