Refs #6031, #7213, add segment label to top level CustomVariables.getCustomVariables report for customVariableName.

Allow new CustomVariable segments to provide all custom variable suggested values by allowing the suggestedValuesCallback to accept Live.getLastVisitDetails data.

Allow Segments to define multiple SQL columns if the segment value can be matched in any of those fields, and use to define two new segments: customVariableName & customVariableValue.

Submodule UI tests: hid user menu from some UI tests + added UI demo to Platform user menu in development mode

If a test case class or fixture class is supplied in TestingEnvironmentManipulator and cannot be autoloaded, throw an exception so some hard to debug test failures can be avoided.

Adding System test case that showcases the bug: ecommerce report with segment "Page URL" shows 0 data