642 add report cli command

[victorgarcia98]

This PR introduces the command flexmeasures add report which allows to create reports (custom calculations defined in classes of type Reporter) and save them to the database or export them to Excel or CSV. It also includes some flags to define the time scope of the report in some predefined ways: --last-hour, --last-day, ...

Closes #642.

[Flix6x]

>1500 lines of code to review is a bit much. :) I think of you update the PR to merge to the reporter branch instead of to main, we should get a nicer separation of the two reviews. When we merge the reporter branch (which will likely happen before this one) the base branch will be automatically updated.

One more thing, have you considered adding review instructions? Like, "here's a cool CLI command that this PR makes possible". Otherwise, I'd start as usual, looking at the tests.

[victorgarcia98]

>1500 lines of code to review is a bit much. :) I think of you update the PR to merge to the reporter branch instead of to main, we should get a nicer separation of the two reviews. When we merge the reporter branch (which will likely happen before this one) the base branch will be automatically updated.

One more thing, have you considered adding review instructions? Like, "here's a cool CLI command that this PR makes possible". Otherwise, I'd start as usual, looking at the tests.

Yes, It wasn't looking good... Thanks for the advice to clean it up.

[nhoening]

@victorgarcia98 why did you close this PR?

[victorgarcia98]

@victorgarcia98 why did you close this PR?

I messed it up adding commits from main and the other branch. I've just opened PR #659 with the changes that I'm proposing.