Reactions: Hide title more comprehensively

[obenland]

Follow-up to #1705.

While #1705 fixed titles for legacy Reactions blocks (v1.0.0), it did not account for hiding titles added through heading blocks, when there are no reactions.

In this PR, we standardize around the v2.0.0 markup with fallbacks for v1.0.0 titles, and then add a hidden attribute when there are no reactions.

See https://mastodon.social/@vsg_DE/114512927652473093

Proposed changes:

• Remove fallback title handling in view.js.
• Always create title markup as a fallback, regardless of whether there's a defined title or not.
• Adds a hidden attribute to the title when there are no reactions.

Other information:

• Have you written new tests for your changes, if applicable?

Testing instructions:

• Go to '..'

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Added - for new features
• Changed - for changes in existing functionality
• Deprecated - for soon-to-be removed features
• Removed - for now removed features
• Fixed - for any bug fixes
• Security - in case of vulnerabilities

Message

Titles added through a Heading block in the Reactions block now stay properly hidden when there are no reactions.

[obenland]

@jeherve Was hiding the new block heading what you were referring to in the previous ticket? If so, I misunderstood.

[jeherve]

It doesn't seem to work for me right now ; I still see the heading on posts where I've had no reactions.

I do use a custom heading title:

<!-- wp:activitypub/reactions {"title":"What people think about it on the Fediverse!"} /-->

[obenland]

I think we need to add a testing infrastructure for these blocks to prevent these regressions going forward.

[obenland]

@pfefferle Have you had a chance to test this yet?

[jeherve]

It seems to work well now, with your fix. 🚢