WCS fixes. (cherry pick of PR #1027 to 1.9 branch)

[SpacemanPaul]

• Check for error after retrieving ranges.

• Use correct dtype when writing out empty data in WCS1 (not required in WCS2).

• Update issue template.

• Ensure correct default behaviour when output and subsetting CRSs match.

• Add (very simple) test.

(cherry picked from commit 79b796f)

PLUS:

• Plug some gaps in permissions management
• Fix some WCS Scaler code that was broken in previous 1.9 PRs, and the corresponding unit tests.

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📚 Documentation preview 📚: https://datacube-ows--1028.org.readthedocs.build/en/1028/

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 5 lines in your changes missing coverage. Please review.

Project coverage is 92.26%. Comparing base (722bc6e) to head (8091fc5).
Report is 34 commits behind head on develop-1.9.

Files with missing lines	Patch %	Lines
datacube_ows/wcs_scaler.py	75.00%	5 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##           develop-1.9    #1028      +/-   ##
===============================================
- Coverage        93.77%   92.26%   -1.51%     
===============================================
  Files               46       52       +6     
  Lines             6573     6882     +309     
===============================================
+ Hits              6164     6350     +186     
- Misses             409      532     +123     

Files with missing lines	Coverage Δ
datacube_ows/wcs1_utils.py	95.25% <ø> (ø)
datacube_ows/wcs_scaler.py	94.15% <75.00%> (-0.04%)	⬇️

... and 4 files with indirect coverage changes