Update to react-router v6

[QJonny]

It needs history v5 and @lagunovsky/redux-react-router (instead of connected-react-router).
The current problem is that redux-react-router does not support immutable.js, which the older one does.

See https://git.epsitec.ch/cresus.tools/bankin-gui/-/commit/e18dd29813915d9acbc6e7540f4733406da512ba and https://git.epsitec.ch/cresus.tools/bankin-gui/-/commit/5290fcadb4bcdd89d031467ebe87e3f1d2c62b90 for migration tips