In Calc, move the `Comment` button closer to the left side on `Insert` tab

[printfdebugging]

This is an Easy Hack. Potential mentors: @Darshan-upadhyay1110

Detailed description and rationale

In Calc, on the Insert tab, the Comment button is located on the rightmost edge. If users want to insert a comment, they would go to the insert tab as they want to insert it. Then the users would scan through the insert tab from left-to-right trying to spot the Comment button.

Just imagine how frustrating it would be for them to scan the whole insert tab and find the Comment button at the end. It would be better if it's placed on the left side of the tab where it's easier/quicker to spot. Probably on the left of the Chart button as a big button (we have plenty of space).

Code pointers

• Control.NotebookbarCalc.js file defines the layout of the calc notebookbar tabs.
• Play around with it to understand the schema
• notebookbar.css to adjust the css properties of the button (if that's required)

cc @pedropintosilva for more input.

[omkarhole]

can you please assign me ?