Improve UI for updating impact stats, allow any admin to do it

[ragesoss]

Currently, the 'impact stats' that are displayed on the home page when you're logged out (in wiki_education mode) are controlled by setting them in /settings.

However:

• The current values don't get loaded, so it's confusing to figure out what to change and you can't easily just change one value while leaving the others as they are
• Only super admins can save changes, but normal admins should be able to do so as well.

[ManishKumar081]

Hi @ragesoss I'd like to work on this issue.

My approach:
Pre-populate the impact stats form with current values from the database on page load and Update the permission check to allow all admins (not just super admins) to save changes.

Please assign this to me and I'll open a PR soon.

[ragesoss]

We don't generally assign issues, but you're welcome to work on it.

[lakshita10341]

@ManishKumar081 Are you still working on it? If not, I'd like to take it up.