Add linear tests with different normalisations

Aims to test that changes in various normalisations still return the same result, once accounting for the normalisation change in the output.

Based on the cyclone test case.

Anticipate four variants ; single species adiabatic electron (implemented), two species electrostatic collisionless (implemented), two species EM collisional (implemented but failing), EM (implemented).

There are six runs per variant, and the collisionless cases take about 2 seconds to run. As such this can start to add a minute or more to the test suite time. We might want to consider restricting this (or some of it) to a higher test level.