[Typography foundations] Deprecate existing typography components #6537
Description
https://github.com/Shopify/polaris/blob/main/documentation/Deprecation%20guidelines.md
Deprecation warnings need to be added in polaris-react and the deprecated flag needs to be added for the following components in the style guide.
Components:
- TextStyle
- DisplayText
- Heading
- Subheading
- Caption
LabelTextContainer- VisuallyHidden