frontends (tools/webrtc): add a options to merge video for PiP and to specify size: - the `merge_pip` option is now used to indicate if local feedback and remote video streams must be merged with local feedback being a PiP of remote video. By default, it's done for `SINKS_AUTO`, but it can be manually specified to use it with `SINKS_APP` or to split ``SINKS_AUTO`` in 2 windows. - target size of the compositor used with `merge_pip` can be specified. By default, 720p is used. rel 428

ARG REVISION
FROM libervia/web:${REVISION:-dev}

LABEL maintainer="Goffi <tmp_dockerfiles@goffi.org>"

ARG DEBIAN_FRONTEND=noninteractive

USER root

COPY --chown=root:root libervia.conf /etc/libervia.conf

WORKDIR /home/libervia
USER libervia