Support f-strings in sorted literals

[SIBTAIN-ASAD]

Closes #2712.

# isort: list currently relies on ast.literal_eval, so a list containing an f-string fails before it can be sorted.

This change:

• preserves each f-string's original source while deriving a sortable key from its rendered content;
• applies the same ordering path to list, unique-list, set, and tuple literals;
• adds direct and end-to-end regression coverage for the __lazy_modules__ example.

Verification:

• uv run pytest tests/unit -q --benchmark-disable (675 passed, 1 skipped)
• uv run ruff check isort/literal.py tests/unit/test_literal.py tests/unit/test_isort.py
• uv run ruff format --check isort/literal.py tests/unit/test_literal.py tests/unit/test_isort.py
• uv run mypy isort/literal.py
• uv run flake8 isort/literal.py tests/unit/test_literal.py tests/unit/test_isort.py

[SIBTAIN-ASAD]

I checked the failed Read the Docs build log. It stopped during the initial fetch with fatal: couldn't find remote ref pull/2716/head, before installing dependencies or building the docs. The build is tied to head c5a4c8d3 and appears to be a transient PR-ref fetch failure rather than a Sphinx or code failure. The other recent isort PR docs builds are passing. A Read the Docs rebuild of this PR should confirm that; I am leaving the tested source change unchanged.