Enhanced view of SysML requirement table (#251)

To begin, there is no table view in the SysML requirements diagram, but there is in the requirements diagram under Other diagrams...

In the current table format it is not possible to expand the height of each entry, which makes such a table difficult to read.

It is not possible to copy a record from the table and paste in a requirements diagram and getting a requirements object, instead some kind of generic box is created.

If you add a sub-requirement and then delete it, the expansion box remains in front of the requirement record.

It should be possible to add other properties such as stereotypes also from the table view.

I believe that a table view is essential in order to maintain a collection of all requirements of a specific type. When learning from several sources on the internet, they all conclude that a requirement table view is extremely useful to avoid cluttered diagrams.