TP - when generating a cert for a DS, the common name field should be editable

[mitchell852]

Currently, the common name is derived from routing name unless the DS is HTTP* where common name would include a wildcard (#1465) and the field is uneditable.

By making the common name field editable, you give the user more freedom to generate the cert as they desire.

https://localhost:8443/#!/delivery-services/:id/ssl-keys/generate

[mitchell852]

This might have created a bug. Allowing the user to specify the common name when regenerating ssl keys for a delivery service will result in a key mismatch like this:

#1855