Context menu opens by clicking anywhere on the app

[adityamahapatra]

The context menu that allows the user to edit an expense opens regardless of where the mouse pointer is positioned. It should ideally open only when the pointer position is somewhere within the QTableView widget.

[adityamahapatra]

A feature has been added now wherein the proper row index is selected in the expense editor window, so this issue doesn't seem to that big a problem as of now. Keeping it open to see if some workaround pops up during the course of development.

Not a priority right now.