Extend GridView focus event to true selection pattern

[evanweaver]

From Andrew's testing:

Selection:

1. When you scroll up or down in the grid view, you lose the yellow selected cell. This makes it impossible to click "Apply to Selected" from a row you have to scroll down to get to.
2. When you click an object in the grid, the cell turns yellow and that object opens in the inspector. Then when you then click inside the inspector to edit that object, you lose the yellow selected cell in the grid. This matters when you are trying to go through the grid and edit each object one at a time, because you can lose your place.

Button activation:
3. "Apply to Selected" button activates even when no rows are selected. (Talk with Marj about whether this should be changed or not, I’m not convinced myself.)

[jmarrec]

1. is the same as NREL/OpenStudio#1545

[macumber]

The selected cell goes out of focus when you click on the scroll bar. There is a work around which is to select all the rows first and then click on the value to apply so I'm not sure we need to keep this issue open.