Create manual regression test suite for the app

[pvginkel]

• Installation:
  • Installation using the MSI.
  • Automatic update works and restarts the app at the end.
  • Manual update using the MSI.
  • Terms of service, product name and author in the installer.
  • Installer installs into the correct folder, shortcuts are created, including the auto start shortcut.
  • Uninstaller works and optionally removes all user data also. Uninstaller must have an option to remove user data #202
  • Uninstaller removes all files and registry keys it installed.
• Development:
  • Publishing NuGet packages.
  • Publishing NuGet symbol packages.
  • Scripts:
    • Prettier script prettifies the correct files, including the WiX XML file and XAML files.
    • Hint (and important etc) blocks render correctly. There's a fixup script for this because prettier breaks the formatting.
    • Prettier script correctly prettifies all playbook scripts.
  • Pipelines:
    • PR pipelines check that prettier & CSharpier has been run and that there are no untranslated keys for the core translated languages.
    • Release pipeline verifies that no files in the MSI were downgraded.
    • Build number and release notes are picked up from the annotated tag.
    • MSI and NuGet packages have the correct build number.
    • Secrets are correctly embedded into the build artifact.
    • API documentation gets updated on push to main.
    • MSI and release notes get published on release build.
• Documentation:
  • DocFX plugins works, i.e. images at 200% DPI are rendered correctly on normal and high DPI devices.