Clickable sponsored image to advert URL

[rebron]

Description

Follow-up issue to #13190.
Allow users to click directly on the sponsored image to the advertisers URL within a predefined click area.

Dependency on #12700

Design

Expected Result

1. Open Brave and view a New Tab Sponsored image.
2. Area under top sites, the middle of the page up until the widget section, should all be clickable. When the cursor is over the image and the click-through can execute, the icon of the cursor should change to the pointer and the click-URL should be displayed in the bottom left of the NTP.
3. When users clickthrough they should be directed to the advertisers URL

Brave version (brave://version info)

n/a

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the nightly channel? n/a

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

May need to address responsive issue first: #12700

Assets

Figma: https://www.figma.com/file/FMuS3IZbzqzQTyRHz42Oix/?node-id=1367%3A47295

[karenkliu]

Designs added!

[rebron]

Closing as dupe of #28736