Support for `fs.cp()`, fs.cpSync()`, `fsPromises.cp()`?

[rauschma]

The following three functions were added in Node.js v16.7.0 and are very useful because they enable you to copy directories recursively. AFAICT, mock-fs does not currently support them:

• fs.cp()
• fs.cpSync()
• fsPromises.cp()

[3cp]

ENOENT: no such file or directory, opendir 'a'

Unfortunately, these new apis use opendir internally.

#319
Currently there is no way to support it, because nodejs has no intention to expose the new fs_dir binding for us to mock.