arrow

GH-40342: [C++] move LocalFileSystem to the registry (#40356)

### Rationale for this change

Moving LocalFileSystem into the registry is a good first usage and will help us hammer out which aspects of built in file systems should remain public.

### What changes are included in this PR?

A factory for LocalFileSystem is added to the registry. `FileSystem::MakeUri` ( https://github.com/apache/arrow/issues/18316 ) is added to enable roundtripping filesystems through URIs. `file://` URIs now support a use_mmap query parameter, and `local://` URIs are also supported as an alias.

<h6 id="reduce">Reducing the set of bound classes</h6>

Some unnecessary bindings to the LocalFileSystem concrete class are removed. This demonstrates that with a registered factory pattern, it is no longer necessary to keep a class hierarchy public for binding. Eventually (if desired), we can move concrete subclasses of FileSystem entirely out of public headers.

### Are these changes tested?

Yes, all existing tests for file:// URIs continue to pass

### Are there any user-facing changes?

For consistency, local:// URIs will now be considered equivalent to corresponding file:// URIs

* GitHub Issue: #40342

Authored-by: Benjamin Kietzman <bengilgit@gmail.com>
Signed-off-by: Benjamin Kietzman <bengilgit@gmail.com>