prefs: fix text-link not clicking on space/enter (#4522)

Fix regression after 117197e11d
where space or enter would not trigger a click on
link outside of the main window.

".keyboard-clickable" is handled by listener in ZoteroPane,
so links outside of it (e.g. preferences) are not affected by it.
For now, just explicitly handle "keypress" event by the
zotero-text-link component.

Also, added a focus-ring around the link so it is visible
when it is focused.

Fixes: #4521

chrome/content/zotero/elements/textLink.js

@@ -9,11 +9,16 @@
 					this.open(event);
 				}
 			}, true);
+			this.addEventListener('keypress', (event) => {
+				if (event.key == 'Enter' || event.key == ' ') {
+					event.preventDefault();
+					this.click();
+				}
+			});
 		}
 
 		connectedCallback() {
 			this.classList.add('zotero-text-link');
-			this.classList.add('keyboard-clickable');
 			this.setAttribute('role', 'link');
 		}
 

scss/components/_textLink.scss

@@ -4,4 +4,5 @@
 	text-decoration: underline;
 	border: var(--material-border-transparent);
 	cursor: pointer;
+	@include focus-ring;
 }