[feat] Make borders optional instead of binding shadows

Describe the problem

In Windows 10/11, I am unable to remove borders while having shadows, This limits the implementation of some UI solutions.

Describe the solution you'd like

I want a parameter to choose whether to keep the border, independent of the shadow option. Because for us developers, customizing a border while preserving shadows is easy (such as defining a border for the body and customizing colors and other effects), and removing the original border is next to impossible (at least I don't seem to see an effective way)

Alternatives considered

I remember the old version seemed to achieve this effect, but I don't know which specific version it is. Perhaps the new version can also be implemented? Just need to put in effort?

Additional context

In my opinion, those who develop applications using webview generally have a high pursuit of application UI, which may require the technology stack to provide higher degrees of freedom I like to use Tauri, hoping that at least in terms of UI, what others can do, Tauri can do too, and what others cannot do, Tauri can do even better.