refactor: use named args shorthand

[arad-starkware]

This change is 

---

Note

Low Risk
Pure refactor of argument passing and struct field initialization in tests and one event emit call; no behavioral changes expected aside from potential compile-time syntax issues.

Overview
Refactors Cairo call sites across flow tests and unit tests to use the named-argument shorthand syntax (e.g., :amount, :staker_address, :pool_contract) for improved consistency and readability.

Also updates StakeOwnBalanceChanged event emission in staking.cairo to use the same shorthand when setting new_self_stake, without changing the underlying values.

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[arad-starkware]

• refactor: use named args shorthand #101 👈 (View in Graphite)
• main

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.80%. Comparing base (9c5b24f) to head (da8a83e).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #101      +/-   ##
==========================================
- Coverage   95.80%   95.80%   -0.01%     
==========================================
  Files          43       43              
  Lines       10519    10517       -2     
==========================================
- Hits        10078    10076       -2     
  Misses        441      441              

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[NirLevi-starkware]

@NirLevi-starkware reviewed 5 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on noa-starkware).

[arad-starkware]

Merge activity

• Mar 31, 8:31 AM UTC: Graphite rebased this pull request as part of a merge.
• Mar 31, 8:40 AM UTC: Graphite couldn't merge this PR because it was not satisfying all requirements (Failed CI: 'test / test').