Migration notes and tips for v0.15 -> v0.18

[llucax]

These are some random notes on migrating from the API version 0.15 to 0.17.

Streamed data samples (ReceiveComponentDataStream)

• rated_bounds in metrics were moved to the component metadata

• component_bounds and system_{inclusion,exclusion}_bounds were merged into samples.metric[x].bounds

• The old VOLTAGE_PHASE_x metric maps to the new AC_VOLTAGE_PHASE_x_N

• Bounds will have at most 2 ranges, which can be mapped to the old inclusion and exclusion ranges roughly like:

  range1, range2 = bounds
  inclusion_lower_bound = min(range1.lower, range2.lower)
  inclusion_upper_bound = max(range1.upper, range2.upper)
  exclusion_lower_bound = max(range1.lower, range2.lower)
  exclusion_upper_bound = min(range1.upper, range2.upper)

  If only one range is present, it can be mapped directly to inclusion bounds.

Extra guarantees for live data

• The same sampled_at value will be used for all metrics in one ComponentData message (response.data)
• There will be at most only one ComponentState in response.data.states

TODO: Maybe document this in the API specs as it is valuable information for anyone using the new API version, even if not doing a migration.