Join Tokens: Web UI support

[avatus]

Teleport should enable join token operations available in tctl tokens in the Web UI

task breakdown:

• Add sort cache service for JoinTokens
• Add grpc methods/pagination for ListJoinTokens
• Create apiserver routes for JoinTokens CRUD
• UI/UX for the web component (prototype done by @avatus , feedback from kenny after)
• Final updates/adjustments to web UI
• Integrate with Discover UI (token reuse)

[zmb3]

@avatus I moved your task breakdown into the existing issue (#31671) which is already linked in our goals doc, just so we don't have multiple issues describing the same work.