Improvements on Form 'Add a device'

[jnadeu]

List of improvements to the form:

• Appeareace and functionality grade should not be mandatory.

• Only will be mandatory type of device, serial number, model and manufacturer fields.

• Remove unnecessary Type of device, remove devices type Diyandgardening, Home and Recreation.

• Width attribute name should be upperletter.

• If you choose Type of Device == Computer, snapshot.manual.device.chassis.l should not be mandatory and change the name to 'Chassis'.

• From Issue Create a ComputerMonitor using 'Add a device' form #61. If you choose Type of Device == ComputerMonitor, add three new fields on form: resolutionHeight, resolutionWidth, size.

[forste]

Started working on this here: https://github.com/eReuse/DeviceHubClient/tree/features/improvements-form-add-device