[Package Renames] Add Package Renames form to "Manage Package" page

[loic-sharma]

The "Manage Package" page should have a new form to rename packages:

The following pieces are tracked in separate issues:

• The message for pending popularity transfers. Tracked by: [Package Renames] Add message for pending popularity transfers on "Manage Package" page #7910
• Add the "Learn more" documentation link. Tracked by: [Package Renames] Document how to apply for popularity transfers #7943

[loic-sharma]

Closing as per #7896 (comment)