Pantalaimon

Fixed

- [[a1ce950]] Allow to send messages using a POST request since Synapse seems to
allow it.

[a1ce950]: https://github.com/matrix-org/pantalaimon/commit/a1ce95076ecd80c880028691feeced8d28cacad9

Changed
- Bump the maximal supported nio version.

Fixed
- Fix our dep requirements to avoid incompatibilities between nio and pantalaimon.

Fixed
- Don't require exact patch versions for our deps.

Fixed
- Bump the version to trigger a docker hub build with the latest nio release.

Added
- Add support for Janus 0.5.0.
- Added media endpoint handling to the /media/v1 path.

Fixed
- Modify media events so they contain the unencrypted URL fields as well.