[feat] Custom titlebar

[abose]

Describe the problem

Have a custom title bar to use the titlebar space better and probably add more bling and chrome to the ui.

An argument against this is the os window context menus are not available: https://discord.com/channels/616186924390023171/1134839157462671511

Describe the solution you'd like

https://tauri.app/v1/guides/features/window-customization/

Alternatives considered

We may not need this if #1293 is addressed, it looks good without a custom title bar.
Also adds the benefits of having the system title bar which will have many system ui properties.

Additional context

tried the tauri API, it works. But in linux, the window decorations still com up and z-index need to be fixed. Also only gonna happen after window ui redesign/move away from custom size calculations.