[iOS] Upgrade course value prop modal implementation

[moiz994]

Introduce a bottom-sheet modal that activates upon upgrade button interaction. This modal should outline the perks of upgrading and display the course's price, reinforcing the value of making a purchase.

Implementation areas include:

• Upgrade banner on My Courses (under course card)
• Course Home/Dashboard For scenarios where access is expired or content is gated, an embedded value proposition should be displayed, detailing the benefits of upgrading to regain access or unlock the content.

For scenarios where access is expired or content is gated, an embedded value proposition should be displayed, detailing the benefits of upgrading to regain access or unlock content.

Acceptance Criteria:

• Modal appears upon interaction with the upgrade button in specified locations.
• The modal design is engaging and aligns with app UI standards.
• Displays all benefits clearly with the course price.
• Encourages users towards making a purchase decision.

Current implementation:
Video demos of upgrade button interaction and modal popping up can be seen in the following:
Course home flow
Gated content flow
My Courses flow

Screenshot: