[Python] Support serialization of Arrow files on disk without the identifier "Feather"

### Describe the enhancement requested

The documentation for [Arrow Columnar Format](https://arrow.apache.org/docs/format/Columnar.html#ipc-file-format) suggests that the separate Feather project has been subsumed into Arrow, and that it (Feather) is really just the canonical serialization format for Arrow tables:

> We recommend the “.arrow” extension for files created with this format. Note that files created with this format are sometimes called “Feather V2” or with the “.feather” extension, the name and the extension derived from “Feather (V1)”, which was a proof of concept early in the Arrow project for language-agnostic fast data frame storage for Python (pandas) and R.

The Python support of Arrow serialization still uses the identifier `feather`: (see [the Cookbook](https://arrow.apache.org/cookbook/py/io.html#write-a-feather-file))

> Once we have a table, it can be written to a Feather File using the functions provided by the `pyarrow.feather` module
>
> ```
> import pyarrow.feather as ft
>
> ft.write_feather(table, 'example.feather')
> ```

This functionality should be kept as is, for backwards compatibility, but I wonder if the `pyarrow` module should just have a `write()` function, without requiring the need to import the `pyarrow.feather` package or use the term `feather`. This would help to reduce confusion about file extensions and the relationship between "Arrow" and "Feather".

### Component(s)

Python