[FIX] web_editor: indent just a line inside table

Inside the cell of a table, indenting had several behaviors:

- if the selection is contained in several nodes elements: indent the
  element child nodes of common ancestor

- if the selection is contained in one or more list items: indent these
  list items

- if the selection is contained in one 'content block': indent the whole
  cell content

The two first behaviors are expected, but the third one is a little odd
and unexpected next to other existing editors behaviors.

With this commit, the third behavior becomes:

- if the selection is contained in one `content block`: indent this
  content block

note: 'content block' is defined as p, pre, h1, h2, ..., blockquote, td

opw-1824647
closes #24182

addons/web_editor/static/src/js/summernote.js

@@ -1856,12 +1856,17 @@ $.summernote.pluginEvents.indent = function (event, editor, layoutInfo, outdent)
     var $dom = $(ancestor);
 
     if (!dom.isList(ancestor)) {
+        // to indent a selection, we indent the child nodes of the common
+        // ancestor that contains this selection
         $dom = $(dom.node(ancestor)).children();
     }
-    if (!$dom.length) {
-        $dom = $(dom.ancestor(r.sc, dom.isList) || dom.ancestor(r.sc, dom.isCell));
+    if (!$dom.not('br').length) {
+        // if selection is inside a list, we indent its list items
+        $dom = $(dom.ancestor(r.sc, dom.isList));
         if (!$dom.length) {
-            $dom = $(r.sc).closest(options.styleTags.join(','));
+            // if the selection is contained in a single HTML node, we indent
+            // the first ancestor 'content block' (P, H1, PRE, ...) or TD
+            $dom = $(r.sc).closest(options.styleTags.join(',')+',td');
         }
     }