output error messages when downloading vscode server

[GitMensch]

helping the user to recognize/handle issues, see discussion in #24

[GitMensch]

ping @jeanp413 for review

[GitMensch]

Any comment on this @jeanp413? Note: we may want to give curl preference that would also fix #76 - if wanted I can rebase and do both in one commit.

[jeanp413]

How does the output log looks after this change? don't think it would be nice if it's polluted with tons of progress lines output

[GitMensch]

In my test this led to 2 additional lines after all the script that is dumped before execution.
One line showed the download information, the other a progress bar. Is that different on your side?

[jeanp413]

I did some test and I think we can use --no-verbose for wget and --show-error --silent for curl, sounds good? otherwise I see it prints lots of this lines

 30700K .......... .......... .......... .......... .......... 64%  548M 0s
 30750K .......... .......... .......... .......... .......... 64%  490M 0s
 30800K .......... .......... .......... .......... .......... 64%  368M 0s
 30850K .......... .......... .......... .......... .......... 64%  378M 0s
 30900K .......... .......... .......... .......... .......... 64%  378M 0s
 30950K .......... .......... .......... .......... .......... 65%  526M 0s
 31000K .......... .......... .......... .......... .......... 65%  606M 0s
 31050K .......... .......... .......... .......... .......... 65%  614M 0s
 31100K .......... .......... .......... .......... .......... 65%  516M 0s
 31150K .......... .......... .......... .......... .......... 65%  522M 0s

[GitMensch]

That's already better than what we currently have (quite), please take that for now, leaving this issue open - I want to check when the printing is updated (likely a TERM setting) and if we can use that - multiple lines are definitely bad.