switch to core API 3.0 branches

[bertsky]

Not to be merged, merely for tracking available v3 branches:

• New processor API core#1240 ... Fix docker cuda deps core#1312 + deps-tf1: fix 7a2c4c7 core#1313
• port processor to core v3 qurator-spk/eynollah#130 ... v3 API release, again qurator-spk/eynollah#151
• Calamari2 ocrd_calamari#118
• Port to v3 ocrd_kraken#44 ... Docker: resmgr shortcut ocrd_kraken#46
• adapt to ocrd v3 ocrd_segment#69
• Port to ocrd core version 3.0.0 bertsky/ocrd_cis#5 ... bertsky/ocrd_cis@2cf3c85
• Migrate ocrd v3 ocrd_tesserocr#216
• Docker resmgr shortcut bertsky/ocrd_wrap#12
• rewrite: Pythonic, ocrd v3, utilise page-level annotation ocrd_pagetopdf#28
• Migrate to OCR-D v3, Pythonize bertsky/workflow-configuration#34
• OCR-D v3, pythonize, sub-page levels ocrd_olena#99
• migrate to OCR-D v3, add tests and CI bertsky/nmalign#1
• migrate to OCR-D v3, add tests, minor fixes, use alternatives if present ASVLeipzig/cor-asv-ann#15
• migrate to ocrd v3 bertsky/ocrd_detectron2#31
• 🔥 remove everything except the cropper and layout analyzer and convert that to OCR-D/core v3 API ocrd_anybaseocr#112
• migrate ocrd v3 bertsky/docstruct#2
• Convert to OCR-D v3 ocrd_froc#19 ... Update Dockerfile ocrd_froc#20
• V3 api qurator-spk/dinglehopper#128
• port to v3 ocrd_olahd_client#12
• migrate to OCR-D v3 ocrd_keraslm#23
• bertsky/ocrd_doxa@a6df2f2
• core v3 ocrd api page-to-alto#40

No v3 ports yet:

• ocrd_fileformat
• ocrd_neat
• ocrd_repair_inconsistencies (discontinued, will be covered by ocrd-segment-repair)
• ocrd_im6convert (discontinued, covered by ocrd_wrap's ocrd-preprocess-image)
• sbb_binarization (discontinued, now covered by eynollah)

[mikegerber]

• I'm working on merging V3 changes into a new dinglehopper release, but it's probably not ready before Easter.
• With ocrd_repair_inconsistencies I would prefer to remove it from ocrd_all. It was basically a one-off script for fix some inconsistencies with some work spaces and as I could not find any users of it, I archived the repo a year ago. (If there's interest for it's functionality again, I would suggest we add that to ocrd-segment-repair.)

[bertsky]

superseded by #456, #457 and #462