[cwproperties] refactor properties form to make it partly overrideable easily (closes #1936782) also fix some pitfalls on the way: * shouldn't capitalize labels, this has to be done in translation files as desired * form_row in CWProperties form didn't return subform as its parent class

[entity] rename Entity._rest_attr_info into cw_rest_attr_info (closes #1942759)

[entity] upgrade fetch_[unrelated_]order to benefit from changes introduced in 3.14 (closes #1942758) of rql generation parts of the ORM now based on rql syntax tree. This allows more powerful and flexible sort control by giving them the syntax tree instead of manipulating string. Also: * prefix new methods by 'cw_' * fix cases that currently crash in 3.14 due to the refactoring