* Show plus promo modal on first view of Home view of each Hub session

* Stub out intro hub plus promo modal layout and implement its buttons

* Remove some unnecessary plus promo modal related CSS

* Continue adding styling for plus promo modal

* Continue styling plus promo modal

* Refactor plus promo modal CSS to improve alignment of elements

* Continue CSS work for plus promo modal

* Implement recommended gold banner in plus promo modal

* Update and tweak plus promo modal design

* Fix path bug in i18n-checker tool. Consolidate redundant entries in messages. Add check icon to plus promo modal. Modify plus promo modal css.

* Additional consolidation of redundant and unused entries in messages

* Factor plus promo modal rendering out to shared component. Implement rendering in panel. Implement display context CSS adjustments.

* Move Plus Promo modal rendering to a PlusPromoModal shared component. Begin to implement conditional panel display logic

* Create ModalPromos background class responsible for modal promo related business logic and state management

* Add local state to Panel to make sure component rerenders after user dismisses promo panel. Send record of promo interaction to background

* Make PromoModals code more robust

* Factor PlusPromoModal rendering out to helper in Panel. Extend conditional rendering logic to account for upgrade version of modal

* Mark PromoModals methods as static. Refine PlusPromoModal implementation and add debug code

* Add logic to hide plus promo modal from Insights subscribers. Cleanup and comments.

* Clean up. Finish string localization in PlusPromoModal

* Add gold ghostie badge svg. Begin fleshing out upgrade plus promo modal design

* Pull non-shared upgrade version of plus promo modal out of shared PlusPromoModal component and into Panel to simplify

* Flesh out upgrade promo modal UI and styles

* Implement panel to tab link for the upgrade to plus button

* Add no thanks link click handling

* Localization-proof upgrade modal CSS. Finalize UI and display logic.

* Implement ability to turn off promotions from inside plus upgrade promo modal