Table editor: add up/down keys to row/col selectors

[RobertoBozzolo]

Following this idea already implemented, it could be good to add up/down keys to rows and columns selectors.

At present, if the table is in hot or normal mode you can click on a cell in the table preview in the Quick Edit window to select the corresponding row/column: going to editing them is made easy this way. However, if the table is in indicator mode you cannot click on the cella to select row and column. The same applies if you want to reach a column/row out of visible area of the table: the only solution to that is to double click on the column or row selector and type in the number you want. Not easy  nor fast, and prone to errors. Much better to click on a button and increment / decrement the active column index

I'm thinking to something like that:

[Wolfgang]

If I may suggest a little modification...

It may be more intuitive to have up/down arrows for the row selector and left/right arrows for the column selector. This then would also allow to add both pairs of arrows to the cell selector without causing confusion