extended Node features

[muhamadazmy]

A node need to be able to set an extended set of flags for itself that should be available on chain (public)

Suggestion

Instead of modifying the node object itself (that require expensive migration) we can have a dynamic set of feature flags separate from the node itself.

The feature flags should be a dynamic type a list of tuples (key, value) means that a node can have a set of features that can be extended when needed without any required migration. I prefer to have a list of tuples over a map so we can have the same key multiple times (say if we have 2 different GPUs attached to a node)

For example:
A node features can look like

[
   ("gpu", "radeon:RX-6800"),
   ("gpu", " nvidia:RTX-3060"),
   ...
]

[DylanVerstraete]

Extra node features or not needed for the GPU story to complete so will be closing this. See: #725