Optimize SVG block caching and remove expensive deep cloning

[stutijain2006]

This PR improves the internal SVG caching mechanism used in block rendering.

Changes-

• Replaced JSON.stringify-based cache keys with lightweight manual string keys.
• Removed expensive JSON.parse(JSON.stringify(...)) deep cloning in cache logic.
• Replaced deep cloning with shallow cloning for docks arrays.
• Applied the optimization consistently across:
  - basicBlock
  - basicClamp
  - argClamp
  - booleanCompare

Why-

• Reduces serialization overhead during block rendering.
• Lowers garbage collection pressure.
• Improves scripting time during startup and block interactions.
• Maintains existing functionality and rendering behavior.

Impact-

• Reduced scripting time during performance profiling.
• No regression in block rendering or movement.
• No layout or functional changes introduced.

[github-actions]

✅ All Jest tests passed! This PR is ready to merge.