bug: regression with cookie header case sensivity

[TorstenDittmann]

Starting version 1.0.0, setting cookie headers are now case sensitive. Meaning passing Lax as sameSite will not work anymore.

Before 1.0.0 it was changed to lowercase before the condition => https://github.com/jshttp/cookie/blob/v0.7.2/index.js#L273C1-L274C51

When consumed directly it is safe by types, however in my case the library is consumed and used by a dependency.

[TorstenDittmann]

Found this too late #189. I still think it might be useful to have this fallback, in my case I have no control over what my auth library is passing to the underlying framework.