• Fix warning found into /var/log/error.log when using PHP 8

• Create / Add phpunit tests

As an intermediate step towards #1015, and various parts thereof, would it be possible to ignore the syntax for features not currently supported, yet use the parts which are supported in trades?
I'm thinking out loud and wondering what effects this may have.

My end goal here is to be able to read a data file https://gitlab.com/snippets/1856416 without errors. Hledger would be able to parse thi

AFAICS there are no docs for the History section:

I would expect them to appear under https://rotki.readthedocs.io/en/stable/usage_guide.html?highlight=history#tracking-accounts-and-balances but that only concerns current balances, nothing historical.

Is this a bug or feature request?

FR

What is the current behavior?

not in the tree

What is the expected or desired behavior?

should be under the section "System"