[IMP] mrp: mrp_view.xml cleanup

- Reorder views per model and per actions
- Remove dead views and actions
- Flatten configuration menu, only the resource submenu is kept
- Rename mrp_bom_tree_view to mrp_bom_line_tree_view (no other xmlids where harmed in this commit)
- Add a view mrp_bom_tree_view for bom list with name and product variant when group_product_variant is enabled