feat: keep empty cells consistent empty

lib/mv_web/live/member_live/index.html.heex

@@ -356,11 +356,9 @@
           """
         }
       >
-        <%= if member.membership_fee_type do %>
+        <.maybe_value value={member.membership_fee_type} empty_sr_text={gettext("Not specified")}>
           {member.membership_fee_type.name}
-        <% else %>
-          <span class="text-base-content/50">—</span>
-        <% end %>
+        </.maybe_value>
       </:col>
       <:col
         :let={member}
@@ -375,7 +373,7 @@
             {badge.label}
           </.badge>
         <% else %>
-          <.badge variant="neutral">{gettext("No cycle")}</.badge>
+          <.empty_cell sr_text={gettext("No cycle")} />
         <% end %>
       </:col>
       <:col
@@ -394,18 +392,17 @@
           """
         }
       >
-        <%= for group <- (member.groups || []) do %>
-          <.badge
-            variant="primary"
-            style="outline"
-            aria-label={gettext("Member of group %{name}", name: group.name)}
-          >
-            {group.name}
-          </.badge>
-        <% end %>
-        <%= if (member.groups || []) == [] do %>
-          <span class="text-base-content/50">—</span>
-        <% end %>
+        <.maybe_value value={member.groups} empty_sr_text={gettext("No group assignment")}>
+          <%= for group <- (member.groups || []) do %>
+            <.badge
+              variant="primary"
+              style="outline"
+              aria-label={gettext("Member of group %{name}", name: group.name)}
+            >
+              {group.name}
+            </.badge>
+          <% end %>
+        </.maybe_value>
       </:col>
       <:action :let={member}>
         <div class="sr-only">