Replace the full size image in the_content with additional MIME type if available

[mitogh]

Summary

Fixes #174

This PR requires:

• #152
• #194

Relevant technical choices

This PR updates the changes introduced by #152 and #194 in order to replace the full size image if present in the new format, (in this case WebP) making sure all images served to the client are in the same format when a new image is uploaded into WordPress.

Checklist

• PR has either [Focus] or Infrastructure label.
• PR has a [Type] label.
• PR has a milestone or the no milestone label.

[adamsilverstein]

Excellent!

[felixarntz]

@mitogh The new code overall looks solid, I found a few small issues that mostly relate to the already existing code, but we had missed them before.

[felixarntz]

LGTM!

Let's wait with merging this though until #194 is ready, since technically the implementation here depends on how we implement #194.

[felixarntz]

Ah nevermind the above, I see you've created this against your branch for #194. I think for the future it would be better to create both PRs based on trunk, since if we merge this now, it would be harder to review #194 as it would include the changes from here which were already approved.

So I'd still say it's better to wait until #194 has been approved before we merge this.

[mitogh]

Thanks, mostly I've created this based on #194 just to have smaller diffs I agree this should is currently being blocked by #194 but having everything based on trunk will create merge conflicts after approval which usually triggers another review, so when having this approved and PR against #194 allows for simpler flow, however, I do see the problem specifically around dependencies between each PR.