Added a claus that checks if a position is removed from all employees during the "removePosition" case.

Fixed an issue with added positions if they didnt exist in the position table, and a bug after removing the last position for an employee then adding a new one.

Now supports position data. Made the made changes to some cases and methods to make distinctions between employees trained positions and positions in general.

Shifts now have a position field, that the schedule classes methods are updated to take positions and return position data.

Server now supports methods for adding and removing positions to the database, including sending messages to the client for updating there local positions.

Added methods for added and removing positions for a given employee. Position information is also gotten when getting employee info.

Moved to new package for server files. Updated UserThread and DataBaseQuery to work with the both Availability and TimeOff classes.

New class for interacting with the TimeOff table in the database. Moved to new package for server files and updated the module-info.java file.

New class for interacting with the availability table in the database. Moved to new package for server files and updated module-info file.