[Feature] 希望增加根据类型区分maxAssets

[zhangweiwei0326]

Version information (版本信息)

• Device: e.g. iPhone6
• OS: e.g. iOS 13.4
• Package Version: e.g. v2.1.0
• Flutter Version: e.g. v1.17.1

Describe the solution you'd like (描述你期望的解决方案)
比如：requestType 为RequestType.common时，希望如果用户选择视频只能选1个，但是选择图片的话就可以选择9个
Describe alternatives you've considered (其他解决方案或疑虑)
A clear and concise description of any alternative solutions or features you've considered.

Additional context (附加内容)
Add any other context or screenshots about the feature request here.

[AlexV525]

我调研了一下微信的朋友圈选择资源，一共有两种情况：

选择视频后，无法再进行选择。目前暂时还无法达成，因为对于所有资源来说都可以多选，后面可以加一个完全匹配微信的模式，但是选择视频确认后不能再选图片是由你自己控制的，屏蔽入口即可。

Is this the case that you're talking about?

[AlexV525]

Some other developers are asking for this implementation, so the feature is started developing when there's no respond from the author.