Added preconnect link tag to speed up google font retrieval

[pnicolli]

Fixes #3328

Add preconnect link tag as suggested by lighthouse. The current SemanticUI configuration requests 4 different font files from this origin, this preconnect should help optimize the connection.

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Test summary

304 • 0 • 15 • 0

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Run details

Project	Volto
Status	Passed
Commit	519b759da4
Started	May 22, 2022 9:53 PM
Ended	May 22, 2022 10:05 PM
Duration	11:40 💡
OS	Linux Ubuntu - 20.04
Browser	Chrome 101

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[ichim-david]

@pnicolli @sneridagh although this improves the current google fonts font loading I wish we could have a pluggable section in the head to add any needed pre-fetching without having to customize HTML.jsx. We miss the slots from plone classic main_template where you could of added many things without resorting to any overrides.

[sneridagh]

@ichim-david agreed. We tried it in the past, but we can't use Pluggables here (they are not SSR-able). I could imagine a setting with an array or Map() of components, then render them all in order? So multiple add-ons could subscribe to it?

/cc @tiberiuichim ?

[tiberiuichim]

We could use a similar model as the AppExtras, where we register in configuration components that will be rendered in that "slot".

[sneridagh]

@tiberiuichim oh sure, I didn't recall that we refactored the appExtras in such a way. 😅

The question that I have now is that if @pnicolli addition should go into such a slot, or has sense to be always there by its own.

However, I would like to have such a slot in place soon, tbh.

[tiberiuichim]

Slots can have "static" components as well. Maybe it's the moment to introduce them, at least the configuration and the static part? https://github.com/plone/volto/blob/slots_quanta_split_form_undo_prefix_path/src/config/slots.js#L4

[pnicolli]

This could be superseded by #3492 and #3493 I will either close or move this forward based on the result of those two.