Application results in error when launched from QGIS 1=3.16.2 and optional string parameters left empty
Description
This bug was reported on the forum.
Since last QGIS version (3.16.2), which includes the improvements developed by @troopa81, one can't launch an application from QGIS if an optional string parameter is left empty, because the application would return the error ERROR: No value associated to parameter -ParameterName.
I tried to launch the application from the command line, with empty strings as parameters, and I get the same error message. It would be interesting if the application didn't crash because of an empty optional parameter. Thus, we may want to fix this in the Application Engine.
Steps to reproduce
Use QGIS to launch the "Segmentation" application leaving the "mode.vector.layername" parameter empty.