[FEA] Add `cudf::gather_every` for selecting every nth row

**Is your feature request related to a problem? Please describe.**
xref https://github.com/rapidsai/cudf/pull/23015#discussion_r3538492967

Polars has a [gather_every](https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.Expr.gather_every.html) operation that allows selecting every nth row from a Column.

**Describe the solution you'd like**
An API probably like

```cpp
std::unique_ptr gather_every(
table_view const& source_table,
size_t n,
out_of_bounds_policy bounds_policy = out_of_bounds_policy::DONT_CHECK,
rmm::cuda_stream_view stream = cudf::get_default_stream(),
rmm::device_async_resource_ref mr = cudf::get_current_device_resource_ref());
```

which from https://github.com/rapidsai/cudf/pull/23015#discussion_r3538492967

> I'm thinking the API can use a counting transform iterator to generate the indices on the fly.

**Describe alternatives you've considered**
Use `cudf::gather` with a gather map produced from `cudf::sequence`

Start by reading the proposed gather_every API and the linked discussion in cudf#23015, then compare the existing cudf::gather and cudf::sequence operations. Done means selecting every nth row from a table with the specified bounds policy, stream, and memory-resource parameters, with tests covering the resulting rows and relevant edge cases.

Written by the indexing model from the issue text.