feat: implement console commands for accessing contract state data

[grandima]

Resolves #1722

Summary

Implements three new REPL commands for inspecting contract data during development:

• ::get_constant <contract> <constant> - Get constant value from a contract
• ::get_data_var <contract> <var> - Get data variable value from a contract
• ::get_map_val <contract> <map> <key> - Get map value from a contract

Implementation Details

• Added command handlers in components/clarity-repl/src/repl/session.rs
• Added help documentation for the new commands
• Added comprehensive tests in components/clarinet-cli/tests/console.rs

Test Plan

• [x] All existing tests pass
• [x] Added unit tests for all three new commands
• [x] Commands work with both valid and invalid contract identifiers
• [x] Error handling works correctly for missing contracts/data
• [x] Help documentation displays properly

REPL demo of interaction with fixtures/mxs/counter.clar contract:

[grandima]

@hugoclrd please check, it's ready for review.

[hugo-stacks]

Hello @grandima Have you seen the review?

Thank you

[grandima]

@hugo-stacks thanks for such a quick and comprehensive review! I'm working on fixes. Meanwhile, I'll convert to draft and tag you when ready.

[grandima]

@hugo-stacks please check again as I applied the suggested changes and attached screenshots.

[codecov[bot]]

Codecov Report

:x: Patch coverage is 61.49068% with 62 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
components/clarity-repl/src/repl/session.rs	61.49%	62 Missing :warning:

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