feat: refactor email tagging system to use labels instead of colors

- Updated EmailContextMenu to replace color tag functionality with label tags.
- Modified EmailListItem to display label badges for emails based on keywords.
- Enhanced EmailViewer to include a tag picker for emails.
- Adjusted ThreadListItem to show label badges for email subjects.
- Added tests for email list item and keyword settings to ensure proper functionality of the new tagging system.
- Updated localization files to reflect changes from color tags to labels in multiple languages.

locales/pt/common.json

@@ -155,9 +155,10 @@
     "back_to_list": "Voltar para a lista",
     "message_details": "Detalhes da Mensagem",
     "more_reply_options": "Mais opções de resposta",
-    "set_color": "Definir cor",
+    "set_color": "Definir etiqueta",
+    "tag": "Etiqueta",
     "more_actions": "Mais ações",
-    "remove_color": "Remover cor",
+    "remove_color": "Remover etiqueta",
     "more_count": "+{count} mais",
     "characters_count": "{count} caracteres",
     "quick_reply_placeholder": "Escreva uma resposta rápida...",
@@ -929,8 +930,8 @@
     "delete": "Excluir",
     "mark_as_spam": "Reportar spam",
     "not_spam": "Não é spam",
-    "color_tag": "Etiqueta de Cor",
-    "remove_color": "Remover Cor",
+    "color_tag": "Etiqueta",
+    "remove_color": "Remover etiqueta",
     "items_selected": "{count} e-mails selecionados"
   },
   "shortcuts": {