Add option to draw layout associated to register on the same plot as the Register

[a-corni]

It is currently hard to visualize what trapping spots have been selected among a layout to define a Register. The layout is stored inside a register. With the option "qubits_color", we can implement the plotting of both layout and register on the same plot:

Suggested by both @SergiJulia94 and @soufianekaghad98

[BrFle]

Hey ! I'd like to start contributing to Pulser, can I be assigned this issue ?

[HGSilveri]

Hey @BrFle , of course! Let us know if you need any help :)

[a-corni]

Hi @BrFle, do you need help to tackle this issue ? 😄

[BrFle]

Hi @BrFle, do you need help to tackle this issue ? 😄

Hey @a-corni ! I got confused with git and actually never published my PR. I got something working, i'm still lacking reasonable tests. Could you go take a look ?
Thanks a lot !
#772

[a-corni]

Thanks @BrFle ! I will have a look !