Pulsestreamer additional

Description

Added button to remove the sequence and to output constant signal.

[ ] Bug fix (non-breaking change which fixes an issue)
[x] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

[ ] My code follows the code style of this project.
[ ] I have documented my changes in the changelog (documentation/changelog.md)
[ ] My change requires a change to the documentation.
[ ] I have updated the documentation accordingly.
[ ] I have added/updated for the module the config example in the docstring of the class accordingly.
[x] I have checked that the change does not contain obvious errors (syntax, indentation, mutable default values).
[ ] I have tested my changes using 'Load all modules' on the default dummy configuration with my changes included.
[ ] All changed Jupyter notebooks have been stripped of their output cells.