Add tooling to embed a base column into a nested column

[hombit]

Feature request

It would be nice if we have a way to convert a base column to a field of a nested column, so the values are repeated for each row. Possible interface:

ndf = generate_data(100, 10)
ndf.add_repeated_nested(ndf["a"], name="nested.a")
# Now ndf["nested"][0] has "a" column and all the values are equal to ndf["a"][0]
ndf.add_repeated_nested("b", to="nested")
# The same, but by base column name, so ndf["nested.b"] is np.repeat(ndf["b"], list_lengths)

It would also require adding lower-level implementations to the accessor and the extension array.

The example use-case: moving band information in ZTF DR23 catalog to light-curves, so we can merge multiple light curves with different passbands later.

Before submitting
Please check the following:

• I have described the purpose of the suggested change, specifying what I need the enhancement to accomplish, i.e. what problem it solves.
• I have included any relevant links, screenshots, environment information, and data relevant to implementing the requested feature, as well as pseudocode for how I want to access the new functionality.
• If I have ideas for how the new feature could be implemented, I have provided explanations and/or pseudocode and/or task lists for the steps.