feat: add debugging logs [CFG-1582]

[teodora-sandu]

This PR exposes a new return value from the ParseModule function, namely debugLogs. This contains extra debugging logs from the parsing, split by file name. The logs can be used in the snyk CLI to provide more context to the user about the error.

The debug logs are only populated for user errors, which we consider actionable.

CFG-1582

[ofekatr]

Excellent work @teodora-sandu
I've left a nit comment and a few small questions, nothing blocking and this looks good to me ✅ 🚀

[ofekatr]

nit: It looks like in the current implementation, we always add an initial newline character.
Could I suggest we instead first aggregate the error messages into a slice with the for loop, then we use the strings.Join function with the newline character?

[teodora-sandu]

The newline is purposeful - have a look at the screenshots in snyk/cli#2769. I want every error to be one line

[ofekatr]

nit: A few small questions about the logs' content:
Would we perhaps want to have the additional error properties available in these logs somehow? Like the calls stack for example?
Should these logs only include error messages?

[teodora-sandu]

I don't think they'd be useful and might even end up cluttering the --debug output too much. If we eventually want to add the stack trace we can, but for now it's more useful to get the actual error message.

[teodora-sandu]

Since this is being called from TypeScript using gopherjs it's a bit complicated to add additional metadata (the easier way to do this is to return a map[string]string like we do here, otherwise the gopherjs interface will struggle to parse the nested values)