Publishing backchannel docker images

[Patrik-Stas]

Hi, what do you think about publishing built backchannel docker images from main branch? I'd be happy to contribute if you agree with this.
Rationale: my laptop is running vpn/compliance software which frequently prevents me from successfully building docker images locally - so my current dev workflow to run AATH while developing aries-vcx backchannel is to actually run it on a linux server, rather than locally. Obviously, I would much rather develop locally (or other workarounds like building docker images externally and pulling them on my computer)