Hide label property as it is not used in the calculator

…line-bugfix

Add changelog entry for empty line printing fix

* test implementation to use map style containers for easier interface and connection editor improvments

* unlock upcoming upgrade routine only for orrect version

* add relevant python helping functions for access

* integration of review

This minimal patch allows to use the python module from gtlab inside python.
In particular it
 - Avoids recreating a python interpreter, if it already exists
 - Only redirects print message, of inside the embedded python interpreter
 - Avoids the destruction of the context manager singleton (yes not nice), as it creates segfaults on destruction. I cannot pinpoint, what it causes

Closes #647

…ble-from-inside-the-python-interpreter

Allow the use of the python module inside a python interpreter

* Use devtools cmake package

* Removed unused MPL license

* Provide backwards compatible GTLAB_DEVTOOLS_DIR variable

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Co-authored-by: marvinoe21 <148885247+marvinoe21@users.noreply.github.com>

* Fixed accessing task from other task groups

I added a small task api, to provide a uniform task access.

Closes #639

* Implemented suggestion from code review

Added Qt6 support

… mode (#652)