H264: Install Janus by default (for WebRTC/H264 streaming)

[jotaen4tinypilot]

In order for us to offer an H264 option in the web UI, we need to install Janus by default.

So the default settings need to be changed:

tinypilot_install_janus: yes

We also need to add

ustreamer_compile_janus_plugin: yes

to make ustreamer compile the janus plugin right away.

⚠️ It’s probably good to wait with this ticket until we have made a decision in https://github.com/orgs/tiny-pilot/projects/12 – depending on the outcome, we also need to write the configuration then.