Add built-in resolution of URLs

[DanGough]

Add a function inside Get-NevergreenApp to automatically resolve the URL provided by each application script, for example to turn:

https://aka.ms/installazurecliwindows

Into:

https://azcliprod.blob.core.windows.net/msi/azure-cli-2.23.0.msi

I could a;so resolve the filename portion of the URL, and the modified date of the file and output that as an extra field.

This is not straightforward:

• Some URLs do not resolve correctly with some user agents
• Some URLs like Github releases and Oracle Java downloads end in what looks like a valid filename, until you resolve the redirects you end up with a query string. You then have to parse the Content-Disposition header to retrieve the filename.
• When querying the header with Invoke-WebRequest -Method HEAD, some URLs refuse to respond, so fallback methods required.

I have old scripts that do this already, they just need polishing and integration.

[JonathanPitre]

This is required for Zoom. Evergreen already has something built-in for this.

[DanGough]

Resolve-Uri function now exists, not using it for every result though, just as and when required.