core, frontends: fix invalid translatable strings. Some f-strings where used in translatable text, this has been fixed by using explicit `format()` call (using a script based on `tokenize`). As tokenize messes with spaces, a reformating tool (`black`) has been applied to some files afterwards.

FROM libervia/web: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