HPO Filter interface

[jdopazob]

• Implement a text box by means of which HPO terms can be selected
• Implement a list of the selected HPO terms from which terms can be removed
• Implement a graphical view of the HPO hierarchy to select the level to select entire branches of the HPO hierarchy
• The selected terms can be used to filter in or to filter out

[mermegar]

Implemented HPO filter interface with all the requirements.