fix(ui): prevent title cards from flickering when quickly hovering across them (#3349)

* fix(ui): remove opacity classes from transition enter and leave props

The flickering was caused by the opacity classes in the `leave` prop to take effect as the
transition ends; when the `leaveTo` prop classes are no longer applied, but the `leave` prop classes
are still applied.

* fix(ui): resolve transition issues for all components

1. Remove opacity classes from `enter` and `leave` props
2. Fix some class name typos
3. Remove transform classes since those are automatically applied as from TailwindCSS v3.0
4. Narrow down `transition` classes to only the properties being transitioned in Transition components

src/components/IssueDetails/index.tsx

@@ -182,10 +182,10 @@ const IssueDetails = () => {
       <PageTitle title={[intl.formatMessage(messages.issuepagetitle), title]} />
       <Transition
         as="div"
-        enter="transition opacity-0 duration-300"
+        enter="transition-opacity duration-300"
         enterFrom="opacity-0"
         enterTo="opacity-100"
-        leave="transition opacity-100 duration-300"
+        leave="transition-opacity duration-300"
         leaveFrom="opacity-100"
         leaveTo="opacity-0"
         show={showDeleteModal}