Custom debugger view using .natvis

[TzuChieh]

It is cumbersome to debug many types as their appearance can be obfuscated by additional structures. Especially for many CRTP math types. What to show in the debugger can be customized, see https://learn.microsoft.com/en-us/visualstudio/debugger/viewing-data-in-the-debugger?view=vs-2022