Searching for a flag name in Audit Log does not show Change Request events for that flag

**Describe the bug**

When I go to the Audit Log of a project and search for a flag name, I expect it to return all events related to that flag - but change request events are missing.

**To Reproduce**

Steps to reproduce the behavior (all in the web UI):

1. Have Change Requests turned on for the Production environment (in our case the number of approving users required is set to 0 - to allow for unilateral overrides in case of an outage - but I can't imagine this matters)
2. Create a new flag in the project
3. Submit a change request to toggle the flag from step 2
4. Approve your own change request
5. Go to the project Audit Log
6. Search for the flag from step 2

**Expected behavior**

The "change request created" and "change request committed" events, which are visible at the top of the log in step 4, show up in step 5 as well.

**Actual behavior**

Only the flag creation events are shown.

**Screenshots**

Not needed IMO, let me know if you need them for some reason though.

**How are you running Flagsmith?**

- [ ] Self Hosted with Docker
- [ ] Self Hosted with Kubernetes
- [x] SaaS at flagsmith.com
- [ ] Some other way

**Additional context**

The underlying Audit Log API also has this problem (that's actually where I originally hit it since I was throwing together a tech debt reduction solution, having not read #184).