This PR adds the UI part of feature flag collaborators. Collaborators are hidden on windows smaller than size XL because we're not sure how to deal with them in those cases yet.
This PR disables the filtering capability in the front end for unknown
users.
Modifying the back end to support filtering for unknown users is not
something we want to do yet. It's possible, but it requires adding a lot
of special cases to the handling code (refer to [PR
#7359](https://github.com/Unleash/unleash/pull/7359)), which we'd like
to avoid if possible. To avoid annoying cases where the filtering
doesn't work as expected and breaks user expectations, we're disabling
the filtering capability for unknown users in the front end.
We can consider whether to enable back-end results for unknown in the future if we get
user feedback that it's important.
This PR works by changing the avatar cell component. When the user has
id 0 (and is therefore unknown), we:
- set aria-disabled to true. This alerts users with assistive tech that
the button is disabled, but it doesn't take it out of the tab order, so
it's not mysteriously missing.
- change the tooltip text, telling users that they can't filter by
unknown users.
- disable the avatar callback function, so clicking on the avatar
doesn't do anything.
The accompanying tests assert this functionality.
I considered also updating the screen reader text, but I think that
would add more confusion or be more information than the user needs.
According to MDN's article on the [aria-disabled
attribute](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-disabled):
> [the aria-disabled] declaration will inform people using assistive
technologies, such as screen readers, that such elements are not meant
to be editable or otherwise operable.
This PR lets you filter by flag creator by interacting with the user's
avatar.
Additionally, I've switched the custom popover for the standard tooltip
that we use elsewhere in the table. This gives the table a more cohesive
feel. As such, I have also deleted the component created in a previous
PR, because it's no longer in use anywhere.
It now looks like this (when tabbed to; notice the focus ring):
