Implement dynamic storage based StorageVec

[ironcev]

Description

This PR is an additional step in implementing #7560. It implements StorageVec<V> for dynamic storage.

Additionally the PR:

• adds comprehensive test coverage for StorageVec in the form of in-language tests. Existing SDK harness tests are deleted in favor of new in-language tests. This is aligned with the agreed strategy to migrate SDK harness tests to in-language tests.
• closes StorageVec::insert() does not work with nested storage types #6040 by properly documenting the semantics of zero-sized types in relation to storage. Every StorageVec<V> methods that does not work with zero-sized types, which are assumed to be nested storage types, is now documented for limitations.
• fixes Fix StorageVec<V>::store_vec and load_vec for non-aligned types #7618 by accepting non-aligned types of any size in store_vec and load_vec and padding them accordingly.
• fixes existing issue of over-allocating memory and having larger amount of slot writes than needed in the quads-based implementation of store_vec.
• consistently add reverts to all existing StorageVec<V> methods in the quads-based implementation that cannot be used with nested storage types. For more details see Breaking Changes below.

When running in-language tests using forc test on the whole workspace two blocking issues occur:

• Many assert_eq calls make compiler panic with too big data section #7612
• forc test process gets killed when run on a workspace with a large number of projects #7613

Workarounds for those issues are commented in code and linked to the issues.

Additional in-language tests for other storage types will be added in a separate PR.

Breaking Changes

Existing StorageVec<V> methods in the quads-based implementation that cannot be used with nested storage types, e.g., swap now consistently reverts if V is a nested storage type.

Previously, those methods:

• sometimes always reverted,
• sometimes reverted in specific paths,
• sometimes executed with undefined behavior.

Consistently reverting can be a breaking change if some existing code called these methods and they were not reverting. Note that such calls represent invalid usage of the storage API (although it was up to now not clearly documented as such) and reverting will actually point to bugs in existing callers code.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[cursor]

PR Summary

High Risk
High risk because it adds a new StorageVec implementation for experimental_dynamic_storage and changes behavior for nested/zero-sized element types (new panics/reverts) plus modifies storage read/write intrinsics coverage, all of which can affect on-chain storage semantics and test stability.

Overview
Implements a dynamic-slot-backed StorageVec<V> (#[cfg(experimental_dynamic_storage = true)]), including new error types (StorageVecError, OutOfBounds) and method implementations that differentiate between non-storage vs nested storage (zero-sized) element types.

Tightens StorageVec semantics for nested storage types across implementations by adding explicit checks/reverts/panics and updating docs; also fixes store_vec/load_vec padding to support any non-word-aligned element sizes (and reduces over-allocation/extra writes in the quads-based path).

Reworks test execution and coverage: CI and justfile now run in-language tests via a new run_in_language_tests.sh (per-project forc test workaround), adds many new in-language contract tests for StorageKey/StorageVec (including dynamic-storage variants) while removing an older storage_vec_insert SDK-harness test, and extends VM/intrinsics tests (e.g., zero-length slot updates/truncation) with updated snapshots.

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[ironcev]

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[cursor]

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[xunilrj]

What is the difference from the declaration above? I am only seeing a small diff on the doc-comments. I think it makes more sense to keep just one and make the difference more explicit.