Fixes in the enrollment process

[teon]

• [x] Add information in the enrollment email that 1) the token is valid 24h and when the enrollment process starts user will have 10 minutes to complete the process
• [x] When the token expires the client/proxy needs to show a toast: Token has expired, please contact your administrator to issue a new enrollemnt token (now its Unexpected error)
• [x] Fix proxy logs - when the token is expired there needs to be information in logs that the user XYZ started the enrollment process but the token is expired, now there are meaningless logs:

proxy_1  | 2024-07-09T11:18:01.800255Z INFO defguard_proxy::handlers::enrollment: 1.2.3.4 POST /api/v1/enrollment/start Starting enrollment process || Tracing data:  http_request: 
proxy_1  | 2024-07-09T11:18:01.802833Z ERROR defguard_proxy::error: 1.2.3.4 POST /api/v1/enrollment/start Unauthorized || Tracing data:  http_request: