Add information about failures to the return result of `dotnet.acquire`

My team owns the [Bicep extension](https://github.com/Azure/bicep), which depends on this extension to acquire dotnet. We're often getting reports of issues with this extension, which have different root causes (some user error, some genuine bugs).

This isn't very clear to our users, so issue reports often get muddled up, or do not contain the relevant information. I've dug around, and can't find any way to obtain information from within the extension calling `dotnet.acquire` to understand **why** the acquisition failed. Would it be possible to return information during failures from this command to give an enum or short description of the failure? This would help us more quickly root cause and differentiate different types of failures.

Here's an example of how we're currently using this extension: https://github.com/Azure/bicep/blob/984361eba389b5fd7ccb2e3fb1a3a0512f68d17b/src/vscode-bicep/src/language/client.ts#L156-L172