Need way to enter URI prefix when adding a registry

[cjmyers]

This is needed when testing with a local SynBioHub

[cjmyers]

When you Add Registry, add another entry called Registry Prefix. When you enter a value into Registry URL, it should be auto-copied into Registry Prefix. The Registry Prefix should not be editable by default. Add a button labeled "Edit" next to Registry Prefix entry. When you select Edit, pop up a window that says "The Registry URL and Prefix should normally be the same value. These usually only differ when you are debugging using a local registry. Are you sure you want to edit the prefix?" This pop-up should have buttons "Yes" and "No". If you select "Yes", make the Registry Prefix editable. If you select "No", do not make it editable.

[cjmyers]

We need to update the entry for new registries to have 3 items:

Registry URL
Registry API
Registry Prefix (blocked as currently by the Edit button and warning, should usually match Registry URL)

Note Registry API and Registry Prefix are the ones used by the backend as currently. Registry URL would be the name used in the list when selecting a registry, like when importing a component.