Notifications: Give approve button more flex space for centering

[StevenDufresne]

Part of DOTMSD-982

Proposed Changes

• Give the notification approve/approved button slightly more flex space (flex: 1.25 vs flex: 1 for other action buttons) so the longer "Approved" text is better centered.
• Add a className prop to ActionButton so individual buttons can be targeted with CSS.

Why are these changes being made?

The "Approved" button text in notification comment actions appeared off-center compared to the other buttons (Spam, Like, Edit) because the longer word didn't have enough space. Giving the approve button 25% more flex space provides better visual balance.

Testing Instructions

1. Open the Dashboard notifications panel
2. Navigate to a comment notification
3. Observe the Approve/Approved button alignment relative to Spam, Like, and Edit buttons

Before (trunk)

After (this PR)

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you tested accessibility for your changes? Ensure the feature remains usable with various user agents (e.g., browsers), interfaces (e.g., keyboard navigation), and assistive technologies (e.g., screen readers) (PCYsg-S3g-p2).
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-169106

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-169106&env=jetpack

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https://calypso.live?image=registry.a8c.com/calypso/app:build-169106&env=a8c-for-agencies

Dashboard live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-169106&env=dashboard

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• agents-manager
• help-center

To test WordPress.com changes, run install-plugin.sh $pluginSlug fix/notification-approved-button-spacing on your sandbox.

[fushar]

Works 👍 Though it might still be a problem in other languages 🤔

[p-jackson]

Yes the assumption that each button can be exactly the same size doesn't feel very language responsive.

But this change is also English-centric. Who's to say "Spam" isn't the largest label? Maybe the suggestion below would work?

Ideally each button label would be able to wrap too 😳 but that sounds even more complicated :D

[p-jackson]

This is short for flex-grow: 1; flex-shrink: 1; flex-basis: 0%;. Starting each button from 0 and giving them all equal space.

What about going with

flex-grow: 1;
flex-shrink: 1;
flex-basis: auto;

Now each button gets to start with its natural width, and then then share out the remaining space from there.