Survey should reject student id that is not a Java identifier

[DavidWhitlock]

A student entered their numeric PSU id for their login id in the Survey and it caused some amount of havoc because it did not lead to a valid package name for their projects.

The Survey program should require the login id to be a valid Java identifier.

See https://docs.oracle.com/en/java/javase/18/docs/api/java.base/java/lang/Character.html#isJavaIdentifierStart(char)