WPF Client: not embed appsettings.json

[phoogers]

The current version of the WPF Client generated by the guidance puts the appsettings.json as an embedded resource. This inherently means you have to rebuild for each target environment, instead of just swapping out configfiles. Please consider not embedding appsettings.json by default unless there is a blocking reason to do this

[HaGGi13]

This was discussed with Gilles and we will not embed the appsettings.json files anymore in future. This will be changed by one of the next Guidance version, not clear which specific Guidance version yet.