Add -insecure to go get command when getting additional tools

[brownwk]

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Is your feature request related to a problem? Please describe.
When the extension want to install things like gopls, it can't as some places use certifcate chains. This is solved by using -insecure in the go get command.
Describe the solution you'd like
I think the issue is in the goGetPackage.ts file. Line 35, I think you need to add '-insecure' after the '-v'. Although this would be better if it was configurable. I don't think everyone would want the default being insecure
Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.
I typicall copy and paste the command it is trying to run in code's terminal and add the -insecure option.
Additional context
Add any other context or screenshots about the feature request here.

[hyangah]

@brownwk thanks for the feature request.

The flag -insecure is going to be deprecated (golang/go#37519) and GOINSECURE environment variable is recommended instead. (See
https://golang.org/cmd/go/#hdr-Environment_variables).

You can set GOINSECURE in "go.toolsEnvVar". You will need this anyway to make other tools such as gopls or go in modules mode to work smoothly.

I filed #825 to allow fine tune the tool installation process, but it's likely that you don't need that.

[hyangah]

Closing in favor of #825.