do validation of ProjectUri parameter

[iricigor]

at the moment whatever is passed at the end will be folder name, even if it is not valid name
for example, module PowerShellGet has ProjectUri this one https://go.microsoft.com/fwlink/?LinkId=828955 and that tries to create directory ?LinkId=828955

In should be expanded to https://github.com/PowerShell/PowerShellGet