feat(pedm): explicitly support elevating .msi files

[thenextman]

By inspecting elevated .msi files launched from Explorer, we see that Explorer invokes %systemroot%\system32\msiexec, with the command line "%systemroot%\system32\msiexec" /i "{path-to-msi}".

We achieve the same in the PEDM module by using the same command if the file extension is .msi. The .msi extension is already being trapped by the shell extension, but previously we would call CreateProcess on the .msi causing "file is not a valid Win32 executable".

Additionally, I polished and added @awakecoding's original "ExplorerCommand.ps1" script. This is useful for debugging, where the installed shell extension can't be overwritten as it's in use by Explorer. Install Devolutions Agent with the PEDM feature; then use the PowerShell to unregistered the shell extension. Swap in your development or debug DLL, then re-register the shell extension. If you supply the .pdb file as well it's possible to attach the debugger to Explorer.exe and debug the shell extension code.

[awakecoding]

wooohoo, you're making my day! good job!

[github-actions]

Let maintainers know that an action is required on their side

• Add the label release-required Please cut a new release (Devolutions Gateway, Devolutions Agent, Jetsocat, PowerShell module) when you request a maintainer to cut a new release (Devolutions Gateway, Devolutions Agent, Jetsocat, PowerShell module)

• Add the label release-blocker Follow-up is required before cutting a new release if a follow-up is required before cutting a new release

• Add the label publish-required Please publish libraries (`Devolutions.Gateway.Utils`, OpenAPI clients, etc) when you request a maintainer to publish libraries (Devolutions.Gateway.Utils, OpenAPI clients, etc.)

• Add the label publish-blocker Follow-up is required before publishing libraries if a follow-up is required before publishing libraries

[CBenoit]

LGTM! Left a few minor comments, feel free to address and merge! 🙂