fix: backport triple colon extension updates

[yufeih]

Backport the changes to triple colon extensions from v3 branch. Fixes #8999

[codecov]

Codecov Report

Patch coverage: 84.18% and project coverage change: -0.05 ⚠️

Comparison is base (1452a59) 76.80% compared to head (15231a6) 76.76%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9000      +/-   ##
==========================================
- Coverage   76.80%   76.76%   -0.05%     
==========================================
  Files         592      592              
  Lines       24735    24795      +60     
==========================================
+ Hits        18998    19033      +35     
- Misses       5737     5762      +25     

Impacted Files	Coverage Δ
...Extensions/TripleColon/TripleColonBlockRenderer.cs	100.00% <ø> (ø)
...xtensions/TripleColon/TripleColonInlineRenderer.cs	66.66% <ø> (+6.66%)	⬆️
...Engine.Extensions/TripleColon/TripleColonInline.cs	42.85% <50.00%> (-28.58%)	⬇️
...digEngine.Extensions/TripleColon/VideoExtension.cs	77.22% <64.06%> (-20.56%)	⬇️
...e.Extensions/TripleColon/TripleColonBlockParser.cs	87.32% <83.33%> (-1.73%)	⬇️
...kdigEngine.Extensions/TripleColon/CodeExtension.cs	94.59% <95.45%> (+0.15%)	⬆️
....Extensions/TripleColon/ChromelessFormExtension.cs	92.50% <100.00%> (ø)
...digEngine.Extensions/TripleColon/ImageExtension.cs	92.63% <100.00%> (ø)
...gEngine.Extensions/TripleColon/TripleColonBlock.cs	100.00% <100.00%> (ø)
...ine.Extensions/TripleColon/TripleColonExtension.cs	95.83% <100.00%> (-0.47%)	⬇️
... and 2 more

... and 2 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.