Implement Material design UI

[oMaN-Rod]

Includes mostly aesthetic changes (eye candy!) along with fill/empty inventory functionality:

• Added MaterialDesignThemes and MaterialDesignColors nuget packages
• Implemented a dialog service and snackbar
• Implemented async sav file loading & saving
• Added an option in preferences to enable/disable a collapsible side bar
• Added an option in preferences to enable/disable dark mode
• Updated the mass dismantle cheat logic a bit, uses a transitioner to go between a coordinate list and coordinate form within a dialog

I wasn't sure about the colors, tried to go with a vibe similar to the game. These can be changed in App.xaml, i.e.

<ResourceDictionary Source="pack://application:,,,/MaterialDesignColors;component/Themes/Recommended/Primary/materialdesigncolor.Orange.xaml" />
<ResourceDictionary Source="pack://application:,,,/MaterialDesignColors;component/Themes/Recommended/Accent/materialdesigncolor.Indigo.xaml" />