Returns Cloud presets and unregistered camera slots.

Cloud preset (source: cloud)
Registered in Lumana Cloud. It has a Cloud ID, name, status and metadata. Its presetToken is the
camera's token for the preset, usually a slot number such as "1".

Native preset (source: native)
Exists on the camera but is not registered in Lumana Cloud. Its ID and name are null; its status is
UNREGISTERED.

Use source to distinguish the two kinds and register a native item before managing it as a Cloud preset.

If camera discovery fails, the endpoint still returns Cloud presets with HTTP 200. Therefore, an absent
native item does not prove that the corresponding camera slot is free. When the camera reports more than
ten presets, only native items "1" to "10" are listed; Cloud presets are always listed, whatever their token.

Required scope: read:ptz