Enhanced information in audit or members list

### Problem Statement

It would be good if there was a way to audit user activity. Specifically to determine if a user is logging into the product. This could be either in the audit log or just as an extra column on the members list.

Otherwise there isn't really a 'good' way to tell if a user is just 'looking' at the data in sentry but not really changing anything.

### Solution Brainstorm

The current members list calls an API like `https://us.sentry.io/api/0/organizations/{org-slug}/members/` to get the data to display the list of members in the org. I've noticed in the JSON response it contains lots of useful information like:

```
"dateJoined": "2024-07-23T13:12:58.190928Z",
"lastLogin": "2024-07-23T14:49:18.404091Z",
"lastActive": "2024-07-23T15:06:25.962741Z",
```

So maybe it could be as simple as surfacing `lastActive` or `lastLogin` in the members list.

### Product Area

Settings - Members