Provide FM command that will wait for a UI to appear

In many circumstances a given UI action results in a request to a backend server and depending on response time variability pausing a script may not be adequate. Providing a command that allows one to wait for a UI element to be present would allow one to reliably control the preconditions for follow-on commands

WaitFor UIView ("Home") <timeout> - command fails if timeout is reached <property> <expected value>