Drymass

- feat: support new "raw-oah" and "raw-qlsi" file formats from qpformat
- enh: write FFTW wisdom to cache directory
- setup: bump qpformat from 0.13.1 to 0.14.0
- setup: bump qpimage from 0.8.5 to 0.9.1
- setup: bump qpretrieve from 0.2.2 to 0.2.8

- BREAKING CHANGE: handling folders in recursive mode changed slightly
- feat: improve metadata extraction from file formats where only
individual images contain metadata and global metadata per file
cannot be used (user is prompted in this case)
- enh: allow background correction with series data file by only
taking the first image (warning is still issued)
- enh: set the default method of sphere analysis to rytov-sc
- enh: reduce default verbosity for image fitting
- setup: bump qpformat from 0.10.6 to 0.13.0
- setup: bump qpimage from 0.6.2 to 0.8.4
- setup: bump qpsphere from 0.5.7 to 0.5.9
- setup: drop support for all Python versions below 3.9
- setup: add direct dependency on qpretrieve 0.2.2
- docs: update tutorials and documentation accordingly

- docs: update how-to-cite sections

- setup: migrate to GitHub actions
- setup: setup.py test is deprecated
- setup: pin tifffile to 2020.5.25 (moving target)
- tests: cleanup; fix tests on Windows

- setup: use tifffile directly to write images (scikit-image has no
externals module anymore)
- setup: bump qpformat from 0.10.4 to 0.10.6
- setup: bump qpimage from 0.6.1 to 0.6.2

- docs: update trouble-shooting section and cleanup design