0031382: Data Exchange - BinXCAF should preserve length unit information

0031382: Data Exchange - BinXCAF should preserve length unit information

Possibility for adding LengthUnit info to XCAF document using special class XCAFDoc_LenghtUnit and XCAFDoc_LenghtUnitTool is implemented.
Package UnitsMethods is split: geom methods were placed to new file GeomConvert_Units which is in the toolkit TKXSBase, internal step scale factors was placed to StepData.
Updated UnitMethods to convert scale factor to different unit types.
Now, XSAlgo::XSAlgo_AlgoContainer is used to update unit info from static interface values.
New Draw command "XSetLengthUnit" and "XGetLengthUnit" for set or get XDE attribute.
Upgraded tests for STEP, IGES, OBJ, glTF, VRML formats to check area regressing with used unit.
Upgraded tests\de test cases to use any units in the "loop back" algorithms.