Better error message when cwd is invalid

[ehmicky]

process.cwd() throws when the current directory does not exist.

Error: ENOENT: no such file or directory, uv_cwd
    at process.wrappedCwd [as cwd] (node:internal/bootstrap/switches/does_own_process_state:138:28) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'uv_cwd'
}

child_process.spawn() also throws when the cwd option's directory does not exist.

Error: spawnSync echo ENOENT
    at __node_internal_captureLargerStackTrace (node:internal/errors:563:5)
    at __node_internal_errnoException (node:internal/errors:690:12)
    ... // 20 lines of stack trace
    at TTY.callbackTrampoline (node:internal/async_hooks:130:17) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'spawnSync echo',
  path: 'echo',
  spawnargs: []
},

There are also other reasons which can make cwd fail such as missing file permissions, pointing to a non-directory, or using a file name too long (libuv uses getcwd on Unix and GetCurrentDirectory on Windows).

When the above problems happen, we should provide with better error messages. The current error messages are confusing as they do not always mention cwd, making it look like the issue is the command not existing. I have actually gotten this myself in the past, and it can lead to long debugging sessions before realizing what the problem is.