TAB Key control to move to adjacent cell [FEATURE REQUEST]

Current Behavior:
When in edit cell mode, TAB key does not do anything. User must press ENTER, and then tab moves to adjacent cell.

Desired Behavior
User should be able to customize the column with a property named "tab_exits_cell" so that if true, when editing pressing the TAB key moves out of the cell. If false TAB pressing reverts to old behavior.

No files or tests are identified in the issue. Start by locating the editable-cell keyboard handling and the column-property configuration, then trace how Enter and Tab currently move between cells. Done means a true tab_exits_cell setting moves focus out of the edited cell with Tab, while false preserves the existing behavior, with coverage for both settings.

Written by the indexing model from the issue text.