Improve testing structure

To start improving our test setup we want to bring the folder structure in line with common practices:

__tests__/{integration,helpers,...}
src

In other words __tests__ should be at the root not inside src. The current long running test should go under test/integration as it depends on the runtime dependencies.

This opens up the possibility to create a new folder structure that mirrors the folders under src with 1 file per file in the production code for unit testing.

All tasks and build steps that depends on the current folder structure will need reviewing and adapting.

This was discussed as a first step to improve the testing with @dolcalmi.

[nicolasburtey]

yup ok. this would also simplify what needs to be in the production docker image. right now we have an ugly script to delete the tests folders: https://github.com/GaloyMoney/galoy/blob/9f4c4ebdcb186664f500ea5420218e3b2b38d047/Dockerfile#L13

[nicolasburtey]

oups yeah you’re right! nevermind my comment above.