Make the Image component AMP-aware

[michalczaplinski]

What:

Make the @frontity/components/Image AMP-aware and remove the Intersection Observer fallback which used to lazily load images in the absence of native lazy loading.

Why:

To complete making AMP a first-class citizen in Frontity: https://community.frontity.org/t/amp-package/388/

How:

Check if the state.frontity.mode === "amp"

Tasks:

• Code
• TSDocs
• TypeScript
• Unit tests
• End to end tests
• Add a changeset (with link to its Feature Discussion if it exists)

Unrelated Tasks

• TypeScript tests
• Update starter themes
• Update other packages
• Update community discussions

Additional Comments

Not linking the issue because I don't want to close it yet when this PR is merged.

[changeset-bot]

🦋 Changeset detected

Latest commit: 5d41a34

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

ESLint Summary View Full Report

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Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[michalczaplinski]

Now, that the mode of the Frontity app can be set to a new value ("amp") I've noticed that in some places the default value was "default" but in others it was referred to as "html".

• it's "html" in merge-packages.ts and file-settings/types.ts and some other tests files.
• it's "default" pretty much everywhere else.

In order to avoid bikeshedding about it, I went ahead and changed the references to "html" mode to "default"

[github-actions]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[michalczaplinski]

https://www.loom.com/share/34fda69daca84616a02a1ac36969bc30

[luisherranz]

Looks great to me! I love when we remove code 😄

Thanks Michal!

[github-actions]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

---

^{Report generated by eslint-plus-action}