Fault breaks with MagmaProtocol outputs

[cdonovick]

Fault breaks when a protocol is used an output type on account of missing debug_name and len

See: #326

[leonardt]

One option: have fault use getattr and default to name if no debug name
Another: have protocol pass through the _get_magma_value_ debug name
Third: have fault check if magmaprotocol, if so get the underlying debug name

I feel like third might be the simplest option, but perhaps we can come up with some clever way to implicitly pass through these methods to the underlying magma value, or do we like having the user dispatch on this explicitly?

[cdonovick]

Id prefer not to have write a debug_name method. In my ideal world lib code would call proto._get_magma_value_().debug_name or do option 1, I have no preference between the two.

Adding debug_name as a mixin to the MagmaProtocol is fine but each mixin method makes the protocol slightly harder to use because I need to make sure I dont alias a name reserved by Magma.