Motion animation export: a study or a joint drive as an animated GIF (#1680)

Thanks @SychPL.

assets/locales/zh.json

@@ -92,6 +92,7 @@
   "Enable rule": "启用规则",
   "Enabled": "已启用",
   "Explode": "爆炸",
+  "Export Animation…": "导出动画…",
   "Export Current View as DXF": "将当前视图导出为DXF",
   "Export Current View as DXF…": "将当前视图导出为DXF…",
   "Export DXF…": "导出DXF…",
@@ -211,6 +212,7 @@
   "Round": "圆角",
   "Rule": "规则",
   "Save Rule": "保存规则",
+  "Save the study as an animated GIF, seen as the viewport shows it": "按视口中的显示将研究保存为动画 GIF",
   "Saved preview. Geometry is being checked before editing.": "已保存预览。编辑前正在检查几何。",
   "Scale factor": "比例因子",
   "Search": "搜索",
@@ -426,6 +428,7 @@
   "cmd.model_threads": "列出螺纹",
   "cmd.motion_delete": "删除运动研究",
   "cmd.motion_export": "导出运动研究",
+  "cmd.motion_export_animation": "导出运动动画",
   "cmd.motion_list": "列出运动研究",
   "cmd.motion_play": "播放运动研究",
   "cmd.motion_study": "运动研究",