Debugger: propose install if delve not found

[dolmen]

When launching debug, if delve is not found an error is reported. The error message doesn't even tell the 'go get' command to run.
Instead one-click install should be proposed.

Note: currently there is no integrated way to install delve: #874.

[ramya-rao-a]

From the debugger side we cannot have a prompt with a actionable option I believe, (I can dig a little more and confirm soon)

What we can do is change the wording of the error message to be more clear

[dolmen]

What we can do is change the wording of the error message to be more clear

👍
As #874 is now implemented, the message could suggest to use "Go: Install tools" on platforms where this is the way to install Delve. Or, for a more generic implementation, it might mention the URL with the Delve install instructions.

[ramya-rao-a]

f93ffd2

Updated to include the url in the messaging