Merging branch 'i737b'  into 'main'.

See merge request !1966

[i737a] SimDataPair: keep uncertainties in experimental data instead of separate Datafield (#737a) ()

Merging branch 'i737a'  into 'main'.

See merge request !1965

Merging branch 'GUI_test_description'  into 'main'.

See merge request !1964

Merging branch 'bindings'  into 'main'.

See merge request !1963

Merging branch 'i739_main'  into 'main'.

See merge request !1962

rm remnants of user_weights. No clue whether chi2 weighting with uncertainties was/is implemented correctly