local check - always show the threshold values in the metrics and graphs if available

On the rationale that Checkmk can only be sure that the status and the threshold value of a local check are meaningful if Checkmk itself determines the status (when 'P' is used for the state), the display of threshold values for local checks was removed with work #12185.

If I, as a test developer, want to include the threshold values in the metrics of my local check then there is a reason for this and I expect them to be displayed accordingly in the GUI as with all other checks.

Hiding the threshold values makes it even more impossible to recognize the very unlikely case that the service status and the threshold values contradict each other.

Checkmk should therefore always display the threshold values if they are present and leave it to the check developers to decide whether a threshold value should be displayed or not.