Inherit `Beam` and `IBeamScan` classes from common base

Classes Beam and IBeamScan share some common functionality and so the should have the common base called e.g. ISource.

The common things which are duplicated now:

• intensity
• footprint
• polarization (but not analyzer!)
• polarizerMatrix (but not analyzerMatrix!)

added Core refactoring simplify labels

added polarization label

changed the description

mentioned in issue #650 (closed)

marked this issue as related to #650 (closed)

marked this issue as related to #651 (closed)

changed milestone to %offspec

assigned to @m.svechnikov

Right now, intensity, polarization and footprint are constant during a scan. This is not necessarily the case in experiment. Therefore we need to preserve the possibility of extending IBeamScan towards variable intensity, polarization, footprint.

footprint factor is not a constant now, only footprint function is.

But yes, on each point of scan every beam property can be changed. We can also scan over polarization, resolution, divergence etc. Also during the wavelength scan the intensity, resolution, beam size and shape will also change as side effect.

So the design of scan as vector of independent beams looks more proper. Some API to set and get the "collective" properties like common wavelength or intensity can be added for each parameter we can meet in individual beam.

This "collective" API may be exposed only to corresponding derivatives of abstract BeamScan. So BeamScan::setWavelength() will affect wavelengths of all beams and should callable from AlphaScan, PolScan(does not exist), but not from LambdaScan and vice versa.

mentioned in merge request !1908 (merged)

mentioned in commit 4f2a6717

closed with merge request !1908 (merged)

mentioned in merge request !2216 (merged)