[FIX] web_editor: handle palette history better

Before this commit several history steps were added when picking a color
and history steps were added when previewing a color.

After this commit history is only updated on color selection and not
during color preview: applying the color relies on execCommand which
adds an history step => no need to add another step upon picking a color
but must be prevented during preview.

task-2599771

closes odoo/odoo#76417

X-original-commit: 4c1956d697a52e4d561e93930bb9e9f5c61e8a35
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>
Signed-off-by: Benoit Socias (bso) <bso-odoo@users.noreply.github.com>

addons/web_editor/static/src/js/wysiwyg/wysiwyg.js

@@ -1108,13 +1108,17 @@ const Wysiwyg = Widget.extend({
                             this.odooEditor.historyResetLatestComputedSelection(true);
                         }
                         this._processAndApplyColor(eventName, ev.data.color);
-                        this.odooEditor.historyStep();
                     });
                     colorpicker.on('color_hover color_leave', null, ev => {
                         if (hadNonCollapsedSelection) {
                             this.odooEditor.historyResetLatestComputedSelection(true);
                         }
-                        this._processAndApplyColor(eventName, ev.data.color);
+                        this.odooEditor.historyPauseSteps();
+                        try {
+                            this._processAndApplyColor(eventName, ev.data.color);
+                        } finally {
+                            this.odooEditor.historyUnpauseSteps();
+                        }
                     });
                     colorpicker.on('enter_key_color_colorpicker', null, () => {
                         $dropdown.children('.dropdown-toggle').dropdown('hide');