Goal: 

• Add the "Snapshots" modal seen in the mocks below (sketch reference here)
• This will be accessed via the "View all snapshots" menu option being added to the kebab in the repositories list view.

Caveats:

• Packages/Errata will show count only
• Showing "Change" is dependent on this ticket
• For now, there will be no link for the Snapshot name
• No checkboxes
• No Search
• buttons at bottom should not say save/cancel, just one button that says close

Acceptance Criteria:

• UI matches mocks
• This functionality will all be hidden by the snapshot feature flag (IE if the org has access or not).