Feature: Implement UI for using Files as open file dialog

[gave92]

Requirements

• Sidebar should be visible
• Toolbar should be hidden
• Tabs should be hidden
• Address bar should be visible
• There should be an open button

[0x5bfa]

@gave92 We have another option to hide almost every detailed features - Compact Overlay.
While we have some dependency properties in AddressToolbar.xaml.cs and toggle these values in MainPage.xaml.cs, I think we should manage them in WindowContext to store application launch type: Default, CompactOverlay, SaveDialogOverride, OpenDialogOverride, then we can inject the context to each view model for controls and let them control visibilities.
What do you think this idea?

[gave92]

Why not, though I haven't been on the project for some time and I'm not too familiar with WindowContext.
Another possibility is to create a specific MainPage and navigate to e.g. typeof(OpenFilePage) instead of MainPage.

[0x5bfa]

That's also a good idea! We'd have to careful to the duplication of codebase.

@cinqmilleans implemented some global contexts that can be used everywhere with single instance using Depenendecy Injection (DI), which means you don't have to rely on view model or view codebehind context.
This enables us to reference many information, such as selected item in layout page or right clicked item in Sidebar or Widget and execute RichCommand (this is also a feature they implemented before, which also enables us to execute commands globally and manage commands via CommandManager using DI).

Since this means RichCommands (Files.App/Actions) rely on those contexts, we are planning to introduce argument (CommandParameter) not to rely and to enable to run truly globally.

Those contexts are somewhat similar to viewmodels of dedicated views but here's how looks:
Those information can be accessed globally