Expand regression tests

[janssenhenning]

We now have the ability to run a CI job of aiida-fleur vs. the develop version of fleur with the regression tests actually running the develop executables (not yet merged into the develop branch see https://iffgit.fz-juelich.de/fleur/fleur/-/tree/nightly_build_against_aiida_fleur). This is a good opportunity to expand the regression tests atleast for the simple technical workflows

EDIT: Now it is on the develop branch and run in the nightly pipeline of fleur
(See https://iffgit.fz-juelich.de/fleur/fleur/-/jobs/344864 for example)

Since the caching plays no role in the develop pipeline this should also not depend strongly on changes to aiida-testing or the archive impliementation in aiida-core

Workflows with no running regression tests (I just put every workchain here, this does not mean it's necessarily practical to implement complete regression tests for all):
NOTE: Checked boxes do not mean the workchain is fully covered but only that we have some regression tests running on the fleur CI

• FleurBandDosWorkChain
• FleurEOSWorkChain
• FleurSSDispWorkChain
• FleurMAEWorkChain
• FleurDMIWorkChain
• FleurCFCoeffWorkChain
• FleurRelaxWorkChain
• FleurBaseRelaxWorkChain
• FleurStrainWorkChain
• FleurCreateMagneticWorkChain
• FleurBaseWorkChain
• FleurOrbControlWorkChain
• FleurCoreholeWorkChain
• FleurInitialCLSWorkChain
• FleurMaeConvWorkChain
• FleurSSDispConvWorkChain