[IMP] web_editor: better show active entry in the text style dropdown

Replace the "¶" icon with the name of the current active text style
entry.

Part of https://github.com/odoo/odoo/pull/73565
task-2496339

Part-of: odoo/odoo#73565

addons/web_editor/static/lib/odoo-editor/src/OdooEditor.js

@@ -1482,7 +1482,9 @@ export class OdooEditor extends EventTarget {
             }
         }
         this.updateColorpickerLabels();
+
         const block = closestBlock(sel.anchorNode);
+        let activeLabel = undefined;
         for (const [style, tag, isList] of [
             ['paragraph', 'P', false],
             ['pre', 'PRE', false],
@@ -1505,8 +1507,21 @@ export class OdooEditor extends EventTarget {
                     ? block.tagName === 'LI' && getListMode(block.parentElement) === tag
                     : block.tagName === tag;
                 button.classList.toggle('active', isActive);
+
+                if (!isList && isActive) {
+                    activeLabel = button.textContent;
+                }
             }
         }
+        if (!activeLabel) {
+            // If no element from the text style dropdown was marked as active,
+            // mark the paragraph one as active and use its label.
+            const firstButtonEl = this.toolbar.querySelector('#paragraph');
+            firstButtonEl.classList.add('active');
+            activeLabel = firstButtonEl.textContent;
+        }
+        this.toolbar.querySelector('#style button span').textContent = activeLabel;
+
         const linkNode = getInSelection(this.document, 'a');
         const linkButton = this.toolbar.querySelector('#createLink');
         linkButton && linkButton.classList.toggle('active', linkNode);

addons/web_editor/static/src/xml/editor.xml

@@ -11,7 +11,7 @@
                 <button type="button" class="btn dropdown-toggle"
                     data-toggle="dropdown" title="Text style" tabindex="-1" data-display="static"
                     data-original-title="Style" aria-expanded="false">
-                    <i class="fa fa-paragraph"></i>
+                    <span>Normal</span>
                 </button>
                 <ul class="dropdown-menu">
                     <li id="paragraph-dropdown-item">