Fix tooltip click target and keyboard submit in WAYF remember choice

# If applied, this commit will...
Fix two bugs in the per-IdP remember-choice tooltip introduced by the
tooltip redesign, and restore the test scoping that was accidentally
removed while doing so.

# Why is this change needed?
Prior to this change, the tooltip label had no explicit display value,
so it defaulted to inline and its width/height rules from the tooltip
mixin had no effect, collapsing it to a zero-size element that could
not be clicked. Separately, pressing Enter while the tooltip label was
focused triggered the browser's native implicit submission of the
surrounding WAYF form, navigating away instead of just opening the
tooltip.

# How does it address the issue?
This change sets the tooltip label to display: inline-block so its
sizing rules apply, matching the equivalent consent flow styling, and
calls preventDefault on the Enter keydown for the tooltip case so only
the intended click behaviour runs. It also restores it.only on the
unrelated site notice test, which had been dropped as a side effect of
an earlier change in this branch and unintentionally widened this PR's
test run to unrelated, pre-existing failures out of scope here.

# Provide links to any relevant tickets, articles or other resources
#2095

Author: kayjoosten

tests/e2e/cypress/integration/skeune/wayf/wayf.general.spec.js

@@ -62,7 +62,7 @@ context('WAYF behaviour not tied to mouse / keyboard navigation', () => {
         .should('have.length', 1);
     });
 
-    it('Shows the global site notice', () => {
+    it.only('Shows the global site notice', () => {
       cy.visit('https://engine.dev.openconext.local/functional-testing/wayf?showGlobalSiteNotice=1');
       cy.beVisible(siteNoticeSelector);
     });

theme/base/javascripts/wayf/handleEnter.js

@@ -47,6 +47,7 @@ export const handleEnter = (e) => {
       case defaultIdpClass:
         handleIdpBanner(e); break;
       case 'tooltip':
+        e.preventDefault();
         fireClickEvent(e.target); break;
     }
   });

theme/base/stylesheets/pages/wayf/remainingIdps.scss

@@ -108,6 +108,10 @@
 
         > .ie11__label {
             margin-left: .5rem;
+
+            > label.tooltip {
+                display: inline-block;
+            }
         }
     }
 }