docs(dotnet): introduce separate csharp viewport option

[avodovnik]

Due to our handling of null, we want to be explicit in the docs, that the user needs to pass in a special value for undefined.

[avodovnik]

The other option here, would be to introduce code examples for all of the languages to demonstrate how to disable the viewport, but that feels like a higher overhead than the proposed solution.

Now, if only we had language-specific notes >:-]

[pavelfeldman]

I'd either follow js or python, no need for unique approach in c#

[pavelfeldman]

https://playwright.dev/python/docs/api/class-browser/#browsernew_contextkwargs - check out no_viewport

[pavelfeldman]

Looks abandoned.

[avodovnik]

@pfeldman In C#, the approach of using a constant is more familiar than using a separate parameter. We also have a ViewportSize.Default for that same reason. The better option would be to have the default value be set by the generator, but that goes against the other options where we say if it's null, the value is default from the driver.

For that reason, I'd like to keep it this way.

[kblok]

@pavelfeldman @avodovnik can we land this PR? :)

[yury-s]

An afterthought: maybe rename it to NoDefaultViewport for clarity?

[kblok]

Not strong to say no, but I don't know if it will bring more clarity. If you start typing ViewportSize. as a static call, you kinda know where you are going to... you are going to No(something).