[BUG] CLI Fails in docker

[joernweissenborn]

When using the command line version within a docker container, qTsConverter fails to due to it needs a graphical backend. This is probably because there is still all graphical parts involved even though the window doesn't get created. I have not dived deeply into this, but most clean solution is probably make a separate executable for the CLI version.

To Reproduce
Steps to reproduce the behavior:

1. Make a docker container with your favorite distro
2. Install qTsConverter following readme within the container
3. Run qTsConverter --help within the container
4. See error

Expected behavior
In CLI mode qTsConverter should not rely on graphical backend

Additional context
I work around this issue by invoking -platform vnc which is available in my docker image

[guerinoni]

Can you try with latest master?