Create Qt docker image with Squish

Create a qt_v6.3.0_linux + squish image and supporting dockerfile for that

We should have the possiblity to have all Squish docker setup in one or two scripts and if any Qt image needs to have squish support, call that script in the dockerfile and get the image ready with Squish. 

e.g. 

ARG QT_IMAGE_FOR_SQUISH_SUPPORT

FROM ${QT_IMAGE_FOR_SQUISH_SUPPORT}

RUN squish-setup-script.sh

## expose relevant env variables