Slider input for jump-to-z feature

[RFSH]

With the addition of the z-index input, users can jump to any specific z-index that they would like. But to do so, they would have to write the z-index. We could make this process easier by adding a slider that allows users to select z-index values from min to max. And after selecting the value, we would just call the same function as jump to z-index (if the specific z-index didn't exist its should already be handled.) So

• [ ] Modify the existing aggregate request to include min and max, and send min and max to osd viewer.
• [ ] Display a slider (most probably between the z-plane-list and z-plane-info).
• [ ] Make sure to call the proper function when the value changes.

A similar feature can be found here: http://homeros.kennedy.ox.ac.uk/webclient/img_detail/2209/?dataset=405

[rastogi-bhavya]

The min values means the value of the minimum available z index in the DB, similarly for max value. After the user drags to a particular value, that z index or the closest z index to that value would be shown, along with appropriate message.

Q. Do we change the z plane list after this operation?

Q. How to position the UI?