Exploring: Adding Captions to Tiled Galleries

[sdixon194]

Fixes ##11794

Changes proposed in this Pull Request:

It's been a while since we've looked at adding captions to tiled galleries, but it's something that is frequently brought up as a feature request. This PR attempts to explore how we might add caption support to tiled galleries in the vein of the core Gallery block refactor.

If someone more comfortable with blocks and reacts wants to take this over, feel free!

Jetpack product discussion

Does this pull request change what data or activity we track or use?

Testing instructions:

• Go to '..'

[matticbot]

Caution: This PR has changes that must be merged to WordPress.com
Hello sdixon194! These changes need to be synced to WordPress.com - If you 're an a11n, please commandeer and confirm D65803-code works as expected before merging this PR. Once this PR is merged, please commit the changes to WP.com. Thank you!
This revision will be updated with each commit to this PR

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Jetpack plugin:

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