[FIX] web_editor, website: define specific dynamic snippet name

Since [1] when the Dynamic Snippet was first introduced, it also
introduced a concept of "inherited" snippets. Specific snippets would
all `t-call` the same template for their rendering.
A mechanism was introduced to deduce the `data-snippet` from the caller
template, but it stored the obtained value in the `t-called` template
itself. Because of this if several "specific snippets" that used that
template had to be rendered, they would all have the `data-snippet`
value of the first one that got compiled.

We could compile the snippet template into something having a
dynamically obtained `data-snippet` value, but then that would be
equivalent to just using a `t-attf-data-snippet`.
All specific snippets already do set a `snippet_name` in the context
because it needs to be added in the classes.

This commit therefore adds a `t-att-data-snippet` attribute on the
base template, and populates with that same value in `onBuilt` for
stable versions.

During forward ports across stable versions, each new caller must be
patched as well - and all patches must be removed in master.

[1]: https://github.com/odoo/odoo/pull/53175

task-2922635

closes odoo/odoo#115566

X-original-commit: 73d2c9f87bf9a1a792f4318325c2e52fc81db5f2
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>
Signed-off-by: Benoit Socias (bso) <bso@odoo.com>

addons/web_editor/models/ir_qweb_fields.py

@@ -59,7 +59,7 @@ class IrQWeb(models.AbstractModel):
                 sub_call = el.get('t-call')
                 if sub_call:
                     el.set('t-options', f"{{'snippet-key': '{snippet_key}', 'snippet-sub-call-key': '{sub_call}'}}")
-                # If it already has a data-snippet it is a saved snippet.
+                # If it already has a data-snippet it is a saved or an inherited snippet.
                 # Do not override it.
                 elif 'data-snippet' not in el.attrib:
                     el.attrib['data-snippet'] = snippet_key.split('.', 1)[-1]

addons/website/views/snippets/s_dynamic_snippet.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <odoo>
     <template id="website.s_dynamic_snippet_template">
-        <section t-attf-class="#{snippet_name} #{snippet_classes} s_dynamic o_dynamic_empty pt32 pb32">
+        <section t-attf-class="#{snippet_name} #{snippet_classes} s_dynamic o_dynamic_empty pt32 pb32" t-att-data-snippet="snippet_name">
             <div class="container o_not_editable">
                 <div class="css_non_editable_mode_hidden">
                     <div class="missing_option_warning alert alert-info rounded-0 fade show d-none d-print-none">