Advertise Instruments capabilities

[alecandido]

In particular, the Controller should declare in a standard way which parameters are possible to be swept in real time.

In this way, Qibolab can decide if a sweeper can not be implemented even before passing the sequence and sweepers to the drivers, and then convert not available sweepers with unrolling.

It could also be done at the level of the platform, that in turn will query the suitable instrument (without leaving the burden to address the correct instrument to the user).

[alecandido]

This is not user-facing, but internal. So it is postponed to after 0.2.0 release.