feat: add no-padding theme variant to tabsheet (#7606)

Author: FrediWa

dev/tabsheet.html

@@ -64,6 +64,7 @@
     <section style="margin-top: 40px">
       <vaadin-checkbox-group label="Tabsheet theme variants" id="variant-group" theme="vertical">
         <vaadin-checkbox label="bordered" value="bordered"></vaadin-checkbox>
+        <vaadin-checkbox label="no padding" value="no-padding"></vaadin-checkbox>
       </vaadin-checkbox-group>
 
       <vaadin-radio-group label="Direction" id="direction-group" value="ltr" theme="vertical">

packages/tabsheet/test/visual/lumo/screenshots/tabsheet/baseline/ltr-no-padding.png

@@ -59,6 +59,12 @@ describe('tabsheet', () => {
           element.setAttribute('theme', 'bordered');
           await visualDiff(div, `${dir}-bordered`);
         });
+
+        // prettier-ignore
+        it('no-padding', async () => { // NOSONAR
+          element.setAttribute('theme', 'no-padding');
+          await visualDiff(div, `${dir}-no-padding`);
+        });
       });
     });
   });

packages/tabsheet/test/visual/lumo/screenshots/tabsheet/baseline/rtl-no-padding.png

@@ -38,6 +38,10 @@ const tabsheet = css`
     align-items: center;
     justify-content: center;
   }
+
+  :host([theme~='no-padding']) [part='content'] {
+    padding: 0;
+  }
 `;
 
 registerStyles('vaadin-tabsheet', [tabsheet, loader], { moduleId: 'lumo-tabsheet' });