feat(a11y): enhance image macro a11y and add custom template filters

[Onibenjo]

Done

[List of work items including drive-bys]

QA

• Check out this feature branch
• Run the site using the command ./run serve
• View the site locally in your web browser at: http://0.0.0.0:8002/
• Run through the following QA steps
• [List additional steps to QA the new features or prove the bug has been resolved]

Issue / Card

Fixes #

Screenshots

[if relevant, include a screenshot]

[webteam-app]

Demo

Jenkins

demos.haus

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.09%. Comparing base (ddf6999) to head (278703b).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2197      +/-   ##
==========================================
+ Coverage   77.96%   79.09%   +1.13%     
==========================================
  Files          16       17       +1     
  Lines        1688     1708      +20     
==========================================
+ Hits         1316     1351      +35     
+ Misses        372      357      -15     

Flag	Coverage Δ
python	79.09% <100.00%> (+1.13%)	⬆️

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