Replaces 'hidden' and 'inline-block' classes with 'opacity-0' and 'group-hover:opacity-100' for external link icons in multiple components. This change enables smoother transitions and better control over the visibility of external link icons on hover.
#### What type of PR is this?
/area ui
/kind bug
/milestone 2.21.x
#### What this PR does / why we need it:
Fix pending comments calculation in post list item
#### Does this PR introduce a user-facing change?
```release-note
None
```
#### What type of PR is this?
/area ui
/kind cleanup
#### What this PR does / why we need it:
Upgrade Prettier and related plugins, and simplify Prettier configuration.
Now, formatting for all packages will be managed by Prettier in the project root directory.
#### Does this PR introduce a user-facing change?
```release-note
None
```
Ryan Wang