[iOS] Upgrade button and messaging on Locked Content

[moiz994]

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

Acceptance criteria:

• UI matches a similar theme as the prod app
• Tapping the upgrade button initiates the mobile store payment processor
• Tapping show more expands the content to show the bullets present in the value prop modal

Resources:

Current implementation video demo: https://drive.google.com/file/d/1wsP9L7xLRQv8RbobX3SX1ZIPIU6gTJxq/view?usp=drive_link

Screenshot:

[forgotvas]

@saeedbashir any updates here? Do we have API to implement that?