In the situation where there is only a single tab, offer the following close tab options:
  1) Close Tab : this option will be disabled if it is the only tab (ideally, always enabled if there’s no technical reason preventing it as mentioned above)
  2) Close Tabs to the Right: this option will be disabled if there is only one tab (ideally, always enabled if there’s no technical reason preventing it as mentioned above)

By making the above change, the behavior will be consistent regardless of whether there is a single tab or multiple tabs open

@kin-hong: the functionality provided here doesn't fully address the user's use case. Users want the functionality described in #14631. I'm going to delete #14631 & restate the functionality in this issue & lets scope out the work to see if we can include it as a patch in ADS v17.

Desired behavior:

-- In the leftmost tab, offer the following close tab options:
1) Close Tab: this option will always be enabled if total # of tabs > 1. Otherwise, disabled
2) Remove the "Close Tabs to the Right" option
3) Introduce "Close Other Tabs" option which will close all other tabs except the currently selected tab

-- In all other tabs: offer the following close tab options:
1) Close Tab: this option will always be enabled if total # of tabs > 1. Otherwise, disabled
2) Remove the "Close Tabs to the Right" option
3) Introduce "Close Other Tabs" option which will close all other tabs except the currently selected tab

W/ the above changes, notice that there is no difference between selecting the leftmost tab vs any other tab. Also note that this behavior will always preserve one tab in the grid. This way, we don't have to handle the technical issue w/ no grid tabs present. 

Currently, we use the grid result component to store "result settings" to be applied for the next query result. Examples of these user settings are: row/column pivoting fields. We should be able to preserve this behavior since there is always one tab present.

Here is an updated behavior:

-- In all tabs: offer the following close tab options:

1) Close Tab: this option will always be enabled
2) Introduce "Close Other Tabs" option which will close all other tabs (including "current" tab). This will be enabled if the total number of tabs > 1

The "current" tab is the result grid tab generated from the last query execution. When it is unpinned, its result settings will be transferred to the new result grid tab after the next query execution. Note, however, that each pinned tabs will retain its own copy of result settings.

With the above behavior, if the "current" tab is closed, then after the next query execution, the new result grid tab will use a new copy of result settings. 

Verified the updated behaviour in ADS v17.0.7-12