Create integration test for ISPyB group comments

In https://github.com/DiamondLightSource/mx-bluesky/pull/832, we added logic to construct and update the ispyb group comment based on the following assumptions on the ordering of events:

If we are using grid detect:
1. FGS ispyb start document received
2. Two OAV snapshot events gives the first part of the group comment
3. Zocalo is triggered and the event from this adds the last part of the comment
4. Stop document clears the group comment field

If we are using grid detect, same as the above but we skip step 2, so the group comment doesn't contain any info about the grid sizes.

We should add integration tests for these which will error if the above assumptions are ever broken. Don't start this until https://github.com/DiamondLightSource/mx-bluesky/pull/828 is done

## Acceptance Criteria
- Make test which uses the `RunEngine` with the proper callbacks, which goes from grid detect to XRC, and makes sure the comment looks correct.
- Same thing but XRC without grid detect