Added features and GUI implemntations for Category and Filter
Includes:
Additional constructor for category oibject the needs a string name
Added functions for searching category model(get all non deleted categories convert list of categories to list of categories names)
Added GUI functionality for add category and remove category options.
Fixes to do:
have building of dropdown category lists build on data changes not just adds them
Implemented GUI functionality For Category Add and Remove functions
Includes:
- //Merge branch 'dev' of https://github.com/tomorrow-nf/wpi-suite-team5 into dev
- add a new category, depending on if it already exsists in the system
- fixed issue of drob downs building duplicat categories
- issue: when triggering rebuild of drop down it updates based on the last state of the model, nit inculding the newest added category
- Issue: with implementing listener system, null pointer exception is triggered from getCategory(string)

Conflicts:
	Calendar/src/edu/wpi/cs/wpisuitetng/modules/calendar/view/CalendarSidebar.java
Implemented GUI functionality For Category Add and Remove functions and additional merge conflicts
Includes:
- //Merge branch 'dev' of https://github.com/tomorrow-nf/wpi-suite-team5 into dev
- add a new category, depending on if it already exsists in the system
- fixed issue of drob downs building duplicat categories
- issue: when triggering rebuild of drop down it updates based on the last state of the model, nit inculding the newest added category
- Issue: with implementing listener system, null pointer exception is triggered from getCategory(string)

Conflicts:
 Calendar/src/edu/wpi/cs/wpisuitetng/modules/calendar/view/CalendarSidebar.java//Merge branch 'dev' of https://github.com/tomorrow-nf/wpi-suite-team5 into dev

Conflicts:
	Calendar/src/edu/wpi/cs/wpisuitetng/modules/calendar/view/CalendarSidebar.java