Items: Enhance Boot Loaders input

[SchoolGuy]

Is your feature request related to a problem? Please describe.

As a user
I want to be able to select valid data from the offered options
so that I don't get confronted with error messages.

Describe the solution you'd like

The input for the boot loaders is at the moment a list of checkboxes. This is incorrect as only a single option can be selected. Furthermore, the list of options is currently hardcoded to the three available bootloaders that generally are available for generic objects.

To improve this we should utilize a Material Select and retrieve the data backing it via the XML-RPC API. The following methods are available for this:

• get_valid_distro_boot_loaders
• get_valid_image_boot_loaders
• get_valid_profile_boot_loaders
• get_valid_system_boot_loaders

Describe alternatives you've considered

None

Additional context

None