[management table] fix and upgrade users and groups management tables to new api

[table views] closes #1986413: refactor TableView, EntityAttributesTableView, PyValTableView See the tickets for a description of the why. * one should now use RsetTableView instead of TableView and EntityTableView instead of EntityAttributesTableView. * a flexible layout object has been extracted, TableLayout * PyVaTableView has been rewritten using the same base class / renderer

[web component architecture] extract LayoutableMixIn from components in the intend to use it in the table refactoring to come.