[views] simplify and fix the TreeView (closes #16055814)
Simplify the (internal) TreeView._init_params() method to get rid of the
useless 'initial_thru_ajax' argument.
The ajax tree view was not working properly when loaded via ajax, for
instance from a lazy tab. This was due to the buggy protection against
double javascript/ css inclusion, which is no more needed server-side as
it is now implemented client-side.
Deprecate use of the initial_thru_ajax argument of the TreeView.call() method.
<table class="attributeForm" style="width:100%;"
tal:attributes="id tab_id | nothing;
class tab_class | nothing;">
<tr tal:iter="widget lines">
<th class="labelCol" tal:content="structure python:widget.render_label(entity)">attrname</th>
<td tal:define="error python:widget.render_error(entity)" style="width:100%;"
tal:attributes="class python:error and 'error' or nothing">
<div tal:replace="structure error">error message if any</div>
<div tal:replace="structure python:widget.edit_render(entity)" >widget (input, textarea, etc.)</div>
<div tal:replace="structure python:widget.render_help(entity)">format help if any</div>
</td>
</tr>
</table>