Destinations should be configurable with a namespace field.

[davinchia]

Tell us about the problem you're trying to solve

Follow up to parts of #1921.

This ticket will handle #1 and #2 in the above issue.

Describe the solution you’d like

Destinations should be able to accept a namespace field for configuration.

More detailed reading:

• Miro Brainstorm
• More detailed Google Docs proposal

Additional context

Add any other context or screenshots about the feature request here.

[davinchia]

Done with 0.21.0-alpha.