refactor (graphql-middleware): Improve rate limiter and others

[gustavotrott]

• Implements CustomRateLimiter once golang.org/x/time/rate was not cancelling disconnected clients properly
• Add env var BBB_GRAPHQL_MIDDLEWARE_MAX_CONN_PER_SECOND=10
• Remove env var BBB_GRAPHQL_MIDDLEWARE_RATE_LIMIT_IN_MS=50
• HTML5 Client will wait 30 seconds (was 1 sec) for server response before creating a new Graphql WS Connection. It will be useful to save the client position in the queue when several users are connecting simultaneously
• Improve websrv/connhandler.go once it was throwing panic errors in extreme situations

[sonarcloud]

Quality Gate passed

Issues
29 New issues
4 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
1.2% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

Automated tests Summary

✅ All the CI tests have passed!