Iced 0.4 and bump version 0.6

Updated iced to 0.4, thanks to the contribution of some widgets to iced_aw, there are no major changes to the code in this update.

This update is mainly an internal update of iced, with more performance optimizations and better memory control.

It's easier to implement a widget, and since the wgpu backend has been updated to the latest 0.12 version, there is no longer any need to open a separate glow feature to compile for OpenGL.

This is a simple 0.6 bump, I have only bumped the relevant parts of the rust code and left the rest of the version untouched.

I'm not sure if I should upgrade the rest of the components to 0.6 together.

My idea is to upgrade them individually, with different versions of different parts, but the overall version is based on localnative_core.

That is, when localnative_core is 0.6.0, that means that localnative is currently 0.6.0, regardless of the versions of the other parts.