Updates the behaviour of the job validation's model memory limit checks: The success messages success_mml gets only returned if the checks were actually run. This omits the success message for example in the single metric and population wizard.
Inconcistencies between AppState and derived custom states for UI components like mlSelectLimit and mlSelectInterval could trigger errors because the parent of a nested object attribute could become undefined. This PR adds additional checks to state_factory.js's get/set/reset methods to reinitialize itself with AppState and fall back to its default state should it not be present within AppState anymore. The original issues were hard to reproduce consistently using the UI only. However the error could be triggered when creating a malformed URL, like replacing the mlSelectInterval:(interval:(display:Auto,val:auto)) part of the URL to something like mlSelectInterval:(undefined). This PR includes additional unit tests which simulate this behaviour and fail without the additional checks provided by this PR.
