Opinionated theme created for left components

[raquelarrojo]

Checklist
(Check off all the items before submitting)

• Build process is done without errors and all tests pass in /lib directory.
• Self-reviewed the code prior to submitting.
• Meets accessibility standards.
• Added/updated documentation to /website as needed.
• Added/updated tests as needed.

Purpose
Created opinionated theme for the components that didn't have:

• Alert
• Box
• Date input
• Dialog
• Link
• Progress bar
• Tag
• Textarea

Added overlay theme input to keep it as the rest of components to:

• Header
• Progress bar

Nav Tabs's default theme review is pending waiting for Nav Tabs tokens.

Description

• Opinionated theme of some components created.
• Themes documentation updated.
• Visual tests updated with opinionated theme.

Closes #1364