Code limit tool

[twliu-dorian]

Add Sierra contract bytecode size calculator

Implements a Python script to analyze Sierra contract class size limits:

• Calculate total bytecode size in bytes
• Count number of felts in sierra_program using jq
• Handle common error cases (missing file, invalid JSON)

Note: Size calculation provides rough estimates - contracts ~49k felts may still hit size limits.

Testing:

• Tested with various contract class JSON files

[danielntmd]

Only merging the tool, main has all up to date branches so I will block all incoming conflicts for this branch