feature: Create Sextant.XamForms Package

[RLittlesII]

Is your feature request related to a problem? Please describe.

Currently there is a need to depend on Xamarin.Forms in order to use Sextant.

Describe the solution you'd like

I think moving forward we will need to move the Xamarin.Forms implementation into a Sextant.XamForms library. This will allow us to target other platforms easier with the root namespace Sextant, similar to what we do with ReactiveUI.Events packages.

[open-collective-bot]

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