Add missing proxy url field to the MessageEmbed.VideoInfo class

[shaksternano]

Pull Request Etiquette

• [x] I have checked the PRs for upcoming features/bug fixes.
• [x] I have read the [contributing guidelines][contributing].

Changes

• [x] Internal code
• [x] Library interface (affecting end-user code)
• [ ] Documentation
• [ ] Other: _____

Closes Issue: NaN

Description

Adds a field to the MessageEmbed.VideoInfo class containing the proxied video url.