use antd design tokens

[interim17]

Use Case

Advances #601

Acceptance Criteria

After installing antd v5:

• wrap App in ConfigProvider
• define some minimal global design token to ensure that ConfigProvider is applying styles in current build

Details

Once we have a working ConfigProvider we can start to replace the styling from less, and from other stylesheets, using the design tokens.

This work could be one or several initial PRs, and then will involve a long term gradual shift from an old paradigm into new deployment of design tokens and possibly of a CSS-in-JS approach going forward.