Add banner to the top of the page if user's browser is not supported

[arsalan-rana]

Description

Some users may be using browsers that aren't compatible with the frontend. In order to avoid this, we need to read a user's user-agent value and then add a persistent banner to the top to say that their browser is unsupported and they should use a supported browser. e.g. of unsupported browser would be Internet Explorer or older versions of Safari.

Acceptance Criteria

• Detect user's user-agent
• Compile list of supported browsers
• Add banner to the top of the page if the user's user-agent is not in the supported browser's list