better support for `version` field

[rbren]

the version field trips me up a lot. It is great when using a normal chart, but it means commit-ish when pulling from a repo.
I often switch between a fork and an official repo, and forget to adjust the version tag accordingly. Either a better error message or using different field names would be helpful

here's what it looks like FWIW

Chart Name: budibase
Status: Failed
Error Reason: Command Failed with output below:
STDOUT: Release "budibase" does not exist. Installing it now.

STDERR: Error: failed to download "budibase/budibase" (hint: running `helm repo update` may help)

COMMAND: helm upgrade --install budibase budibase/budibase --namespace budibase --version master -f /tmp/tmpcdz9wgv_.yml

took me like 30m to realize what was wrong the other day, despite having hit it like 10 times before :face_palm: