Migrate from Poetry to uv, improve workflows, drop support for Python 3.8

[rlaphoenix]

• Python 3.8 is no longer supported, this was simply required to modernize the package management and build systems. Anyone who still needs to use Python 3.8 for Windows 7 support should look into alternative methods like using unofficial installers, or just update Windows.
• Poetry is no longer used as the package manager or build tool. I have migrated to uv with the hatchling build-system. This improves speed, reliability, and flexibility, giving a much more modernized and future-forward outlook.
• The version number now has one singular source, the __version__ variable in __init__.py. This version number will be used automatically in pyproject.toml as well as inside the InnoSetup installer when used in the CD workflow. The version number can be updated with uvx hatch version "1.2.3".
• Various tooling is now added for linting, formatting, type-checking, and various other checks. Including pre-commit so that future commits have sanity checks contributing to consistency in new code changes across the repository.
• The CI workflow now checks linting and types with ruff and mypy. In the future I may also check formatting using ruff, but not for now. This will bring improved reliability when making further changes in the future.
• Release builds no longer pre-build Homebrew Menu or AIO Switch Updater NSPs. Build these yourself if needed.
• When opening the project in vscode, you will now be recommended to install various extensions that are good to have with the newly added or altered tooling, like extensions for ruff, mypy, and isort.
• Appropriate badges have been added to the README, as well as a small redesign to make the first section more consice and readable.
• ClickableLabel and FileDropWidget widgets have been removed and replaced with a single FileDropper event filter that does the job of both, through event filters instead of a widget that messes with the other widget's layouts. The NRO image can now be changed by dragging and dropping an image.