[#62454712] Storage profile should be provisioned using name only

A storage profile may have the same name in different vDCs, but it will have different hrefs.

This change allows the user to just specify the name to provision a storage profile.

It is a non-breaking change. In a different branch, I have committed a change to the structure of the input. That is a breaking change so I have not included it in this PR. https://github.com/alphagov/vcloud-tools/commit/1716de4c290e48d3150dbd4648d104fa3554c0f3

edit: I have now included the breaking change in this PR and will update the version and documentation accordingly when we decide to merge.