chore: adds toast notification on members settings (#327)

frontend/messages/en.json

@@ -348,7 +348,10 @@
     "user_name_or_email": "User name or email",
     "close": "Close",
     "add": "Add",
-    "are_you_sure": "Are you sure you want to delete member?"
+    "are_you_sure": "Are you sure you want to delete member?",
+    "member_added": "Member added",
+    "role_changed": "Member role changed",
+    "member_deleted": "Member deleted"
   },
   "Settings": {
     "project_management": "Project Management",

frontend/messages/ja.json

@@ -349,7 +349,10 @@
     "user_name_or_email": "ユーザー名またはメールアドレス",
     "close": "閉じる",
     "add": "追加",
-    "are_you_sure": "メンバーを削除してもよろしいですか?"
+    "are_you_sure": "メンバーを削除してもよろしいですか?",
+    "member_added": "メンバーが追加されました",
+    "role_changed": "メンバーのロールを更新しました",
+    "member_deleted": "メンバーを削除しました"
   },
   "Settings": {
     "project_management": "プロジェクト管理",

frontend/messages/pt-BR.json

@@ -348,7 +348,10 @@
     "user_name_or_email": "Nome de usuário ou e-mail",
     "close": "Fechar",
     "add": "Adicionar",
-    "are_you_sure": "Tem certeza de que deseja excluir o membro?"
+    "are_you_sure": "Tem certeza de que deseja excluir o membro?",
+    "member_added": "Membro adicionado",
+    "role_changed": "Função do membro alterada",
+    "member_deleted": "Membro excluído"
   },
   "Settings": {
     "project_management": "Gerenciamento de Projetos",