feat!: Make all types reflect reality and run mypy everywhere

[erlendvollset]

v8 overview: https://cognitedata.atlassian.net/browse/DM-3055

• removes templates
• fixes nullable vs required attributes on all types
• run mypy everywhere
• some special care to diagrams/vision/contextualization APIs since the code there had a high spaghetti factor

[codecov]

Codecov Report

❌ Patch coverage is 94.71074% with 32 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.27%. Comparing base (67de20c) to head (abebe8d).
⚠️ Report is 71 commits behind head on v8-change-requests-to-httpx.

Files with missing lines	Patch %	Lines
cognite/client/data_classes/contextualization.py	91.92%	13 Missing ⚠️
cognite/client/_api/diagrams.py	83.33%	7 Missing ⚠️
cognite/client/data_classes/datapoints.py	77.77%	6 Missing ⚠️
...nite/client/data_classes/transformations/schema.py	90.47%	2 Missing ⚠️
cognite/client/_api/documents.py	50.00%	1 Missing ⚠️
cognite/client/_api/files.py	83.33%	1 Missing ⚠️
cognite/client/data_classes/assets.py	97.61%	1 Missing ⚠️
cognite/client/data_classes/sequences.py	91.66%	1 Missing ⚠️

Additional details and impacted files

@@                       Coverage Diff                       @@
##           v8-change-requests-to-httpx    #2311      +/-   ##
===============================================================
+ Coverage                        90.08%   90.27%   +0.19%     
===============================================================
  Files                              171      169       -2     
  Lines                            25353    25047     -306     
===============================================================
- Hits                             22839    22611     -228     
+ Misses                            2514     2436      -78     

Files with missing lines	Coverage Δ
cognite/client/_api/ai/tools/documents.py	78.57% <ø> (ø)
cognite/client/_api/annotations.py	95.65% <100.00%> (ø)
cognite/client/_api/assets.py	97.71% <ø> (ø)
cognite/client/_api/entity_matching.py	95.83% <100.00%> (+1.49%)	⬆️
cognite/client/_api/events.py	100.00% <ø> (ø)
cognite/client/_api/functions.py	94.46% <ø> (ø)
cognite/client/_api/geospatial.py	92.95% <100.00%> (+0.25%)	⬆️
cognite/client/_api/raw.py	88.93% <ø> (+0.81%)	⬆️
cognite/client/_api/relationships.py	98.85% <ø> (ø)
cognite/client/_api/sequences.py	94.56% <100.00%> (-0.33%)	⬇️
... and 48 more

... and 8 files with indirect coverage changes

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[haakonvt]

Happy mypy, happy life!

[haakonvt]

Merged manually into #2273 due to github currently being set to squash-only