Add Google Sheets tab management commands

[hwellmade]

Hi! It would be very useful if gog sheets could manage worksheet tabs, not just cell ranges.

Right now, common workflows still require opening the Google Sheets UI just to:

create a new tab
rename a tab
delete a tab
This breaks automation for tracker-style sheets (e.g. outreach tracking, project tracking, CRM-like workflows).

Suggested commands:

gog sheets tab add --title "Strategic Outreach"
gog sheets tab rename --from "Sheet1" --to "Cold Outreach"
gog sheets tab delete --title "Old Tab"
optionally: gog sheets tab list
This seems like a natural extension of the existing Sheets support.

Thankx