Inconsistent error messages when credentials fail to save error

[t1m0thyj]

Sometimes we use the secureSaveError helper method to show a pretty error message.

Other times when calling config.save, we only show "Failed to load Keytar module" which is not a particularly helpful message.

[zFernand0]

We may want to standardize on the prettier error message. secureSaveError

Marking as good first issue.