Some miscellaneous ci and documentation additions

[nialov]

Hey, went through the package for the purposes of general build file and documentation cleaning. Currently a draft until I have tested the new CI additions. None of the changes are required and some are subjective changes so if something should be kept as is (like keeping requirements.txt), just let me know and I will revert the change here.

• build: clean python dependency management
• docs: cleaned and updated documentation
• ci: add docker build job
• ci(tests): use use poetry
• build: enable calling toolkit as module

[nmaarnio]

Hey, I think these look great improvements at a glance. Shoot when with a review request when you're ready!

[nialov]

I will do some minor changes still, like making a new Dockerfile instead of messing up the old so if someone is using it they can continue. Also sorry about making formatting changes to the documentation, they are a bit annoying to review but changes to contents itself are minor. There mostly were some old instructions on how to develop etc. that I changed to reflect the current guidance. I will also make a comment here with a list of the actual changes I made.

[nialov]

Changes:

• Made tests.yaml use poetry for installing dependencies instead of requirements.txt.
• Removed requirements.txt and setup.py. As I understood, these are not used outside tests.yaml which I changed. This will remove the need to separately maintain requirements.txt.
• Cleaned and updated documentation
• Added docker.yaml GitHub Action that uses the new Dockerfile-docs for testing poetry installation with pytest and builds the documentation using mkdocs. It also uploads the built pdf as an artifact so it can be downloaded. This checks that the docker and documentation is built successfully. pdf artifact from this pull request e.g. https://github.com/GispoCoding/eis_toolkit/actions/runs/7250994119/artifacts/1121907364
• Added eis_toolkit/__main__.py so that you can do python3 -m eis_toolkit to run the toolkit from command-line.
• Updated docs/dependency_licenses.md

These should be the most major changes. Ready for review. As said before, some changes are subjective and anything can be reverted. Just wanted to show the changes that I would personally make.

[nmaarnio]

I think all of the modifications/additions are good, and can't find any issues. So, ready to merge for my part! But since you updated GH actions, I wonder if we should enable the macos-latest test as part of this PR and see if it works now? I disabled it previously because it suddenly started failing everytime, and didn't really look into the matter

[nialov]

macos tests ran successfully.