[IMP] Added Dockerfile for wkhtmltox v0.12.6-1

[alexandregaldeano]

Compared to the other Dockerfiles:

1. I use Ubuntu 20.04 instead of 18.04
2. I changed how the deb file is installed (dpkg -i + apt -f install)
3. I added the minimum number of dependencies such that rendering is exactly the same as in Odoo.sh
4. I added the --platform flag to avoid pulling the arm64 image which is incompatible with the deb file
5. I Fixed some warning at image build time

I also added the compose file to go along with it.

This Dockerfile is also useable on Apple Silicon. Note that I first tried to make a Dockerfile for arm64, but the pdf rendering was very flacky.

[sbidoul]

Looks good overall, thanks!

Could you

• group all the RUN commands for installation in one, for a more compact image, like it is done in the other Dockerfiles?
• update the GitHub workflow
• remove the docker-compose part from this PR? I'd rather discuss that independently as I'm not convinced of the added value for this project

[alexandregaldeano]

Done, I'll create the PR for the docker-compose.yml file later. I also changed the image version number in docker run command. Thanks for all the inputs!

[alexandregaldeano]

I know realized that I forgot to add the 0.12.6.1 version to the tests. Now, it's done :)

[sbidoul]

I know realized that I forgot to add the 0.12.6.1 version to the tests. Now, it's done :)

Yeah, this build and test in separate files is not optimal :/

[alexandregaldeano]

I kept the Focal version on a branch on our repo, we won't use it, but if someone realizes the Jammy version ends-up affecting the rendering vs Odoo.sh, it will be there: https://github.com/foodles-tech/kwkhtmltopdf/tree/agaldeano/add-0-12-6-1-wkhtmltox-dockerfile-focal

[sbidoul]

Thanks for this contrib @alexandregaldeano