Enhance messaging on the "permission denied" page for incidents

[srabraham]

Currently when a user goes to the incidents list (e.g. for 2024), and if they don't have read or write access to the event, they'll just get a page like this:

I first-handedly saw multiple instances this year of Rangers not knowing how to proceed when they got this error. There were two categories of problem that came up, and I'd suggest we enhance the messaging to cover both of these:

1. The Ranger shouldn't have access to incidents, and really they just need to create an incident report. The page could educate them about incidents vs. incident reports.
2. The Ranger should have access to incidents, but they don't have it. For example, this came up mid-event this year, when one of my fellow Green Dot Leads (GDLs) was unable to view/edit Sanctuary-related incidents, and she was totally confused about what was wrong. Having decent experience with IMS myself, I recognized the problem and escalated a request for incident access for GDLs. Anyway, the "permission denied" message was vague and unhelpful for my colleague.

I'm interested in tech team feedback on this (such as @wsanchez @chaoticbear)