Define isolation state within database

Once a top-level group or Organization is determined to be isolated we will mark that entity as isolated. This will enable other features such as isolation enforcement or promotion to Organization.

The proposal is to have a table per entity with corresponding models:

• namespace_isolations
• organizaiton_isolations

Each with the same set of attributes:

• isolated:boolean not null, default false
• updated_at:timestamp
• created_at:timestamp

The updated_at will indicate the last time the isolated state was changed or confirmed.

The namespace_isolations will have an additional not null namespace_id:foreign_key.

The organization_isolations will have an additional not null organization_id:foreign_key.