feat(expr-ir): Add date_range, support {date,int}_range(eager=...)

[dangotbanned]

What type of PR is this? (check all applicable)

• ✨ Feature

Related issues

• Child of feat(RFC): A richer Expr IR #2572
• Related issue feat: Add support for nw.int_range for eager backends #2895

Description

date_range was spun out from (#2895 (comment)).
Currently supporting day/week intervals only. Month/quarter/year would need dedicated support from the backend.

eager=... is adapted from #2895.
The main improvement here is in the typing:

from typing import Any
from typing_extensions import assert_type
import pyarrow as pa
import narwhals._plan as nwp

expr = nwp.int_range(0, 10)
series = nwp.int_range(0, 10, eager="pyarrow")

assert_type(expr, "nwp.Expr")  # ✔️
assert_type(series, "nwp.Series[Any]")  # ❌ "assert_type" mismatch: expected "Series[Any]" but received "Series[ChunkedArray[Any]]" Pylance(reportAssertTypeFailure)
assert_type(series, "nwp.Series[pa.ChunkedArray[Any]]")  # ✔️