Improve performance of PowerShell installer

[MarkTiedemann]

On my machine, install.ps1 is ~7x faster if I switch from Invoke-WebRequest to curl.exe and from Expand-Archive to tar.exe.

Before:

PS C:\dev\deno_install> measure-command { .\install.ps1 } | select -expand totalseconds
13,1810087

After:

PS C:\dev\deno_install> measure-command { .\install.ps1 } | select -expand totalseconds
1,8624925

This is similar to what's mentioned in #154:

As brought up in #153, since early 2018, curl and tar are available on Windows 10 by default. Thus, on a modern Windows 10 installation, curl could be used to download files and tar could be used to extract a .zip file.

The new implementation would look like this:

curl.exe -Lo $DenoZip $DenoUri

tar.exe xf $DenoZip -C $BinDir

If this proposal would be accepted, #216 could be closed.