PicView

Bump version to 4.2.1 in Directory.Build.props

Use `Uri.LocalPath` instead of `Uri.AbsolutePath` for startup file path retrieval in macOS #336

Bump package dependencies: R3 to 1.3.1, R3Extensions.Avalonia to 1.3.1, Avalonia to 11.3.17, Avalonia.Desktop to 11.3.17, and Microsoft.NET.Test.Sdk to 18.6.0.

Bump package dependencies: Magick.NET-Q8-OpenMP-x64 to 14.13.1, SharpCompress to 0.48.1, Microsoft.NET.Test.Sdk to 18.5.1, and coverlet.collector to 10.0.1.

Add keybinding for "OpenInExplorer" action #338