Traditional non docker environment for backend development

[jerryfletcher21]

What does this PR do?

Builds on #1363.
This PR adds a setup for a traditional non docker regtest environment for backed development and testing.
scripts/traditional/README.md with all the informations.

Checklist before merging

• Install pre-commit and initialize it: pip install pre-commit, then pre-commit install. Pre-commit installs git hooks that automatically check the codebase. If pre-commit fails when you commit your changes, please fix the problems it points out.

[Reckless-Satoshi]

This is super useful! What about we base the tradition-environment over main instead of over split-host-port given how traumatic that fix is?

[jerryfletcher21]

This is super useful! What about we base the tradition-environment over main instead of over split-host-port given how traumatic that fix is?

It would be a bit less clean since we would have to extract the port from the variables, but it is of course straightforward to do.