0027272: FixMissingSeam function creates G1 seam curves

Method BRepLib::EncodeRegularity() is improved to set regularity GeomAbs_CN for edges lying on the same-domain surfaces (where derivatives on both surfaces are equal in all points).

DRAW command getedgeregularity is added to query regularity of the edge on specified faces.
DRAW command edgeregul is removed (this functionality is provided by command encoderegularity).

Added tests: bugs modalg_6 bug27272, bug27383_1, bug27383_2

Correction of shape name in test case for issue CR27272

src/BRepFeat/BRepFeat.cxx

@@ -23,7 +23,6 @@
 #include <BRepBuilderAPI.hxx>
 #include <BRepFeat.hxx>
 #include <BRepLib_MakeFace.hxx>
-#include <BRepLProp.hxx>
 #include <BRepTools.hxx>
 #include <BRepTopAdaptor_FClass2d.hxx>
 #include <ElSLib.hxx>