Remove JRPCSelfContainedBlockHandler and use native alternative

[gcotelli]

No description provided.

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (474fd9c) 99.83% compared to head (18f1ee5) 99.53%.

Additional details and impacted files

@@                  Coverage Diff                  @@
##           release-candidate     #177      +/-   ##
=====================================================
- Coverage              99.83%   99.53%   -0.31%     
=====================================================
  Files                    165      164       -1     
  Lines                  13007    12994      -13     
=====================================================
- Hits                   12985    12933      -52     
- Misses                    22       61      +39     

Files	Coverage Δ
...e/Stargate-JSON-RPC/JsonRPCRequestHandler.class.st	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.