feat(controlplane): make organization names unique

[migmartri]

• Adds a database constraint to make sure the organization names are unique
• migrates the existing data to make sure it meets such constrant
• the process of automatically generating orgs, now makes sure the org doesn't exist by checking for conflicts and retrying if needed.
• org.Create checks for duplicates too.

Closes #523

[danlishka]

Love it, thanks!