feat: include a alias_display attr for Switch, Link, and Interface and expose on their dict and json values

[viniarck]

In the front-end, there's always that requirement of trying to display user friendly displayed value for a Switch, Link, and Interface, which boils down to trying to display a metadata.[node_name|link_name|port_name] (respectively) or fallback to their id value if the metadata value is empty or not set. This code has been repeated all over many components in the UI, this should be implemented in the back-end and then the UI just read this alias_display or whatever it'll be called.

Here are a few examples where that gets (re)implemented over and over in many UIs components:

• https://github.com/kytos-ng/mef_eline/blob/master/ui/k-info-panel/show_circuit.kytos#L729
• https://github.com/kytos-ng/sdntrace_cp/blob/master/ui/k-toolbar/main.kytos#L167
• https://github.com/kytos-ng/pathfinder/blob/master/ui/k-info-panel/best_path.kytos#L34