enh(viz): update landmark/distance adaptors to work on data::Series

Description

These changes update adaptor::SLandmarks and adaptor::SImageMultiDistances so that it works using the new FiducialsSeries API. These adaptors can now works with a ImageSeries (which will use the inner FiducialsSeries), but is retro-compatible and can still works with data::Landmarks (for adaptor::SLandmarks) and data::Image fields (for adaptor::SImageMultiDistances). In SImageMultiDistances, the adaptor will try to cast the data::Image to data::ImageSeries. If it succeeds, it'll use FiducialsSeries, else, it'll use fields.

Closes #1107 (closed)

How to test it?

Launch SightViewer, check that both landmarks and distances work correctly, using data::Landmarks/plain data::Image and data::ImageSeries. There should be no regression.

Additional tasks

• !966 (merged) must be merged first.