Email notification of algo runs doesn't properly report success or failure

[bctcvai]

If the /rest/Email endpoint fails to run correctly, the code in api/kube.py does not log an error.

Additionally, the context for sending the e-mail runs at the user-context causing rest/Email to be exposed to any user with execute permissions.

It may be more secure to limit email sending ability.

This could be done if the exit handlers run in a different account context than the initiating user, which seems fine given the code path is statically defined. Presumably that context would just be allowed to send e-mails.

Currently any user with EXECUTE permissions on a project can send an email to any user on that project as though it came from the tator deployment.