Fixes a problem with the label of the profiler been too long

Description

This too long name was creating problems when doing the comparison, stating wrongly that a profiling region was already used if the first 25 characters were identical.

This is now prevented by forbidding to define labels longer than 25 characters (LABEL_LEN). The code is fixed accordingly.

Closes #630 (closed)

News snippet

Minor fix for the internal time profiler.

Checklist

• I have checked that my code follows the Octopus coding standards
• I have added tests for all the new features added in this request.