Simplify handling of device factories

[DiamondJoseph]

After the state of device factories is settled, the code that calls those factories could do with being neatened.
Currently, there are undocumented kwargs that are passed through to the device_instantiation method.
Once all devices are ophyd-async and can use the device_factory decorator, make_all_devices can have the same method signature as the connect method on the DeviceInitializationController callable.

Acceptance Criteria

• There is one way of denoting/configuring a device factory
• There is one way to get all of the device factories in a beamline
• There is one way to get the devices created by all of the device factories on a beamline
• The standard is documented as part of the dodal documentation