[PT1-866] Add calldata parse library

[SteMak]

Rename Calldata lib to CalldataSlice to clarify the purpose
Implement CalldataParse lib allowing efficient packed value parse

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Note

Low Risk
Changes are limited to new parsing utilities and a library rename with test-only call sites; no bounds checking in CalldataParse is intentional but callers must enforce offsets themselves.

Overview
Introduces CalldataParse, a gas-oriented library for reading left-aligned packed values from bytes calldata via at(shift) → CalldataWord → as* helpers (addresses, uint8–uint256, bytes1–bytes32, and MSB-indexed asBool). at uses inline calldataload and does not bounds-check, as documented.

Renames the existing slicing library from Calldata to CalldataSlice (same slice APIs and behavior) and updates CalldataSliceMock / CalldataSlice.test.ts accordingly.

Adds CalldataParseMock and a Hardhat suite CalldataParse.test.ts covering byte offsets, bool bit extraction, addresses, and all supported uintN / bytesN widths.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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