refactor: add new row button position and show only when necessary

Signed-off-by: Pranav C <pranavxc@gmail.com>

packages/nc-gui/components/smartsheet/Grid.vue

@@ -1094,10 +1094,10 @@ function addEmptyRow(row?: number) {
       </a-dropdown>
     </div>
 
-    <div class="absolute bottom-4 left-4 z-4" @click="addEmptyRow()">
-      <a-button v-e="['c:row:add:grid-bottom', { footer: true }]" class="!rounded-xl">
+    <div v-f="isAddingEmptyRowAllowed" class="absolute bottom-1px left-2 z-4" @click="addEmptyRow()">
+      <a-button v-e="['c:row:add:grid-bottom', { footer: true }]" class="!rounded-xl" size="small">
         <div class="flex items-center">
-          <component :is="iconMap.plus" class="text-pint-500 text-xs ml-2 text-primary" />
+          <component :is="iconMap.plus" class="text-pint-500 text-xs" />
           <span class="ml-1">
             {{ $t('activity.addRow') }}
           </span>