Improve small-window layout for package pages

[Gabriel Dufresne (GabrielDuf)]

This pull request improves the responsive layout of the packages page, ensuring that the toolbar and package views adapt gracefully to different window sizes. The main changes include making the toolbar collapse to icon-only mode on narrow windows, and updating the grid and icon views so package cards stretch to fill available space, closely matching WinUI's behavior.

Responsive toolbar and layout improvements:

• Added logic to track and control the visibility of toolbar button labels in PackagesPageViewModel, allowing the toolbar to collapse to icon-only mode when the window is narrow. This prevents toolbar buttons from overflowing off-screen. (src/UniGetUI.Avalonia/ViewModels/SoftwarePages/PackagesPageViewModel.cs, src/UniGetUI.Avalonia/Views/SoftwarePages/AbstractPackagesPage.axaml.cs, src/UniGetUI/Pages/SoftwarePages/AbstractPackagesPage.xaml.cs)
• Updated the XAML for the WinUI CommandBar to enable dynamic overflow and automatic overflow button visibility, improving toolbar usability on smaller screens. (src/UniGetUI/Pages/SoftwarePages/AbstractPackagesPage.xaml)

Grid and icons view enhancements:

• Introduced observable properties for grid and icon card widths in the view model, and added logic to dynamically compute the optimal width for each card based on the available viewport size. This ensures cards stretch to fill each row and reflow as needed, minimizing wasted space. (src/UniGetUI.Avalonia/ViewModels/SoftwarePages/PackagesPageViewModel.cs, src/UniGetUI.Avalonia/Views/SoftwarePages/AbstractPackagesPage.axaml.cs) [
• Updated the grid and icon views in XAML to bind the ItemWidth property of the WrapPanel to the computed card widths, and removed fixed widths from individual cards to allow them to stretch. (src/UniGetUI.Avalonia/Views/SoftwarePages/AbstractPackagesPage.axaml)

Minor UI adjustments:

• Adjusted the column widths in the data grid for package name and ID to use proportional sizing, improving table layout consistency. (src/UniGetUI.Avalonia/Views/SoftwarePages/AbstractPackagesPage.axaml)

These changes significantly improve the application's usability and appearance on a range of window sizes, especially for users on smaller screens.