User Persona tags UI improvements

[nicopace]

With #78, we are using tags to mark pages based on user personas and those tags can already be seen at the bottom of each page using the tags interface that is used by default on Docusaurus.

Now, let's...

1. improve usability by showing this specific set of tags that are related to the user personas in a better location where the user can identify this right away, e.g. the top right corner of the page, above the title of the page. In so doing, we can also show them with a helpful legend like "👥 User personas:" The way to implement this is doing swizzle of the Doc item.
2. add the possibility to mark blocks of pages with certain user personas tags so those blocks are only expanded if the user persona tag is being used in the navigation. The implementation of this functionality is not clear.

[rudokemper]

Let me know if you want me to pair with you a bit on the second requirement.

And please remember to add this issue to the Guardian Connector Work Queue, assign yourself, add to sprint, etc. ;)

[nicopace]

I am pushing this requirement to the next sprint, so I can address other urgent matters, and while I wait for feedback on the current tagging, as this is an improvement over the requirement itself.