replace react context by valtio

[SamueleA]

TODO: add valtio for kit checkout

[pkieltyka]

please lets not add valito..

[SamueleA]

please lets not add valito..

What are the reasons for not using Valtio?
Currently, we're doing state management with React Context only. Valtio would simplify how we're doing state management.

[pkieltyka]

my hope is we can keep sequence kit very lean. but I think it would be fine if we used it on some subpackages.. I will defer to @corbanbrook what he wants to do

[corbanbrook]

Im not against valtio, we use it successfully in other projects (market-app) and people seem to like it. Its rather small, similar in size to most other state management libs. I do respect that we want to avoid adding any unnecessary bloat, and we have a working solution with React primitives (context, useState), but as applications get more complicated its generally thought that the react primitives fall a little flat and easier DX with other state management libs.