[FIX] web_editor: keep each style when editing link

Before this commit editing a link that was saved with fill styles
did reset it to a different value and even changed the 'type' to 'link'.

After this commit re-editing the link works for each style.

task-2629461

closes odoo/odoo#75512

X-original-commit: 4f6cc912260c5b5689b0e87644ad119ef5a1389c
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/widgets/link.js

@@ -109,7 +109,7 @@ const Link = Widget.extend({
                 const subValues = value.split(',');
                 let subActive = true;
                 for (let subValue of subValues) {
-                    const classPrefix = new RegExp('(^|btn-| |btn-outline-)' + subValue);
+                    const classPrefix = new RegExp('(^|btn-| |btn-outline-|btn-fill-)' + subValue);
                     subActive = subActive && classPrefix.test(this.data.iniClassName);
                 }
                 active = subActive;