ide: Adds ability to delete rows in grids in Project Options.

Ctrl+Del now deletes the focused row. Ctrl+Ins was already implemented
to append a new row.
ide: After reloading a unit, restore the previous scroll position.

This needs some more improvement, by also restoring the edit cursor
position. But for this, the fpg_textedit needs to be improved first.
ide: minor compiler option tweak in the Lazarus IDE project file.

I enabled AnsiString as the default string type.
ide: Refactored StringGrid modification shortcuts

Now we can reuse that code in other areas of the IDE.
ide: Grid Modification - restore focus row as best we can.
ide: set minimum width and height for main window.
ide: increase Messages grid text width.

Still not an ideal solution, but better on larger screens.