[DAEMON-250] @appcd/plugin-ios: New iOS simulator runtimes are not picked up after install

Description

*This is probably an improvement as I can't find any reference to us currently attempting to do this* If I install a new iOS simulator runtime in xcode, then the daemon will not pick it up. Looking through the code, I think we need to set up a watcher on [xcode.globalSimProfilesPath](https://github.com/appcelerator/ioslib/blob/6189855ebc055f85957b93bf4bbe595189607396/src/xcode.js#L29) in ioslib and rescan xcodes and simulators on change.

Steps to reproduce

* Start the daemon appcd start * Call the ios info endpoint for xcode info appcd exec /ios/latest/info/xcode, make note of the simRuntimes property * Install a new sim runtime through Xcode (Xcode->Preferences->Components) * When finished call the ios info endpoint again, noting the simRuntimes property for the xcode you installed the runtime in

Actual

No new runtime is detected

Expected

New runtime should be detected