Add application icons

[jemrobinson]

:white_check_mark: Checklist

• [x] You have given your pull request a meaningful title (e.g. Enable foobar integration rather than 515 foobar).
• [x] You are targeting the appropriate branch. If you're not certain which one this is, it should be develop.
• [x] Your branch is up-to-date with the target branch (it probably was when you started, but it may have changed since then).

:vertical_traffic_light: Depends on

n/a

:arrow_heading_up: Summary

IMPORTANT: I am confident that merging this will not affect the findings of the ongoing penetration test

• Add application icons for
  • Gitea
  • Hedgedoc
  • /data folder
  • /output folder
  • /shared folder

:closed_umbrella: Related issues

n/a

:microscope: Tests

Tested on a fresh SRE deployment

[github-actions[bot]]

Coverage report

Click to see where and how coverage changed

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
data_safe_haven/infrastructure/programs/sre
gitea_server.py					339, 353
hedgedoc_server.py					318, 332
user_services.py					97, 122
workspaces.py					59-60
Project Total

This report was generated by python-coverage-comment-action

[jemrobinson]

@JimMadge : These changes feel bigger than the original PR now. Can you start a new PR for them and revert this to 6d0da02?

Edit: I've made a new branch better-ansible-runtime-variables for these changes and reverted this branch.