This is a massive Frankenstein PR that would be better split up in several independent PRs. However, that splitting up a lot of work and unlikely to yield much benefits in the future, so it's not done.
What's in this PR
Include code for several missions (Athena, Arcus, Lynx, AXIS) into marxs. This code had been previously developed separately, since none of it is really ready for public consumption (e.g. the Lynx concept has been rejected, Arcus is under continuous redefinition). However, given how few people except me currently use MARXS, "practicaility beats purity" and I'm now including this into marxs. Note that the mission code generally is not documented in the docs and not tested. It's simply either not interesting enough for general users (but needed to replicate some of my SPIE proceedings so I want it publicly available) or evolving too fast to write good docs and tests (e.g. the Arcus effective area changes every time the coating or layout changes, tests that check Aeff are thus more checks on the CALDB than on the code).
A number of updates that were developed for those individual missions and are now included into marxs proper, e.g.:
A class to make certain plots that display the performance loss for misalignments.
This is a massive Frankenstein PR that would be better split up in several independent PRs. However, that splitting up a lot of work and unlikely to yield much benefits in the future, so it's not done.
What's in this PR