feat: add array_normalize scalar function

[crm26]

Which issue does this PR close?

Part of #21536 — split of #21371 into one-function-per-PR. Third in the series after #21542 (cosine_distance) and #21861 (inner_product).

Rationale for this change

Adds array_normalize(array) — the L2-normalized version of a numeric input vector. Computed as array[i] / sqrt(sum(array[i]^2)) per element. Returns the same shape as the input (List<Float64> or LargeList<Float64>).

Aliased as list_normalize to match the array_X/list_X convention used across the crate.

What changes are included in this PR?

Coercion shell mirrors the merged cosine_distance/inner_product pattern:

• coerce_types accepts List/LargeList/FixedSizeList of any numeric inner type, plus bare NULL. After coercion the inner function only sees List(Float64) or LargeList(Float64).
• Per-row L2 norm computed inline (no shared module), using a single as_float64_array(list_array.values()) downcast plus value_offsets() slicing — no per-row downcasts.
• Manual list builder: Vec<f64> for values, Vec<O> for offsets, NullBuffer for row validity.

Per-row semantics:

• NULL row → NULL output
• NULL element in list → NULL row
• Empty list → empty list (no division-by-zero hazard)
• Zero magnitude → NULL row (consistent with cosine_distance's zero-magnitude → NULL)
• Otherwise → divide each element by sqrt(sum-of-squares)

Are these changes tested?

Yes. SLT covers:

• 3-4-5 right triangle, 3D vector, already-unit-axis, single non-zero component, negative components
• Bare NULL input, NULL element in list, zero vector, empty array
• LargeList, FixedSizeList (via coercion), Float32 and Int64 inner types, integer literals
• Multi-row query mixing normal / NULL row / zero-vector row / null-element row
• Plan error for non-list input
• No-args error
• Return-type assertion (List(Float64))
• list_normalize alias coverage (constant + multi-row with NULL)

Are there any user-facing changes?

New scalar function array_normalize (alias list_normalize), documented in docs/source/user-guide/sql/scalar_functions.md.

[Jefffrey]

Use NullBufferBuilder here instead. One benefit is when finishing it, it may output None if there are no nulls (currently we always provide a null buffer even if there are no nulls)

[Jefffrey]

I think it might be simpler to use OffsetBufferBuilder here