Proposal: API for setting sidebar title and icon

[twschiller]

Context

• The browser.action API has methods setTitle, setIcon, setBadgeText, and others for configuring the UI of the browser action
• The panel dropdown in the sidebar appears to use the icon and short_text from the manifest

Motivation

• The icon and title can provide information about the state/applicability of side panel. For example, in a page annotation/commenting extension, the number of results for the current page
• Provide affordance for custom branding

Proposed API

• Both browser.action and browser.sidePanel have affordances for setting different options per tab. The API for configuring the side panel entry should also support varying options by tab
• I see two potential approaches:
  • Expose a setTitle/setIcon/setBadgeText/setBadgetTextColor/setBadgeBackgroundColor method on browser.sidePanel
  • Add an optional properties on PanelOptions title?: string, icon?: imageData | object, badgeText?: string, etc.
• Depending on which approach vendors prefer, I can help clarify the detailed API