FilterWheel Refactor

**Is your feature request related to a problem? Please describe.**
Right now, the filterwheel class is messy especially in the yaml file. It would be nice to not have to list every filter as a subdevice of filter wheel since all the info is already contained inside the filterwheel.

**Describe the solution you'd like**
I'd like to remove the subdecive filters from the yaml but sill be able to call filter.enable(). The easiest solution I can think of is to input a function called something like unpack_filters that iterates through filters in filter wheels and create filter device objects. It would be called in the[ _create_device](https://github.com/AllenNeuralDynamics/voxel/blob/e527be932f9fce6c6ebcee35035feff42651f520/voxel/instruments/instrument.py#L49C4-L77C86) function in the instrument if the device type is an filter wheel.

**Acceptance Criteria**
- [ ] remove filters as subdevices of filterwheel
- [ ] still be able to call filter.enable() instead of going through the main filterwheel