Add image carousel for officers with multiple images

[michplunkett]

Fixes issue

https://github.com/lucyparsons/OpenOversight/issues/1045

Description of Changes

Added image carousel for officers with multiple images and additional test coverage.

Screenshots (if appropriate)

Multiple images:

Single image:

No images:

Tests and linting

• [x] This branch is up-to-date with the develop branch.
• [x] pytest passes on my local development environment.
• [x] pre-commit passes on my local development environment.