[BE] Gracefully handle redis disconnects

[liana-p]

🌟 What is the purpose of this PR?

Gracefully handle redis disconnects to not crash the app and let it reconnect.

🔍 What does this change?

• Fixes an issue in a function that was called on a setInterval which would try to access an undefined object after a redis disconnect and crash the app
• Added logging for various redis events so we get clear logs when redis errors/reconnects.

🔗 Related links

• Auto reconnect when redis connection is lost (internal)

❓ How to test this?

Turn off the redis docker container while the app is running and see those events in the log, then turn it back on and see the app reconnects to redis, recovers and continues to work as expected.

[semgrep-app]

Semgrep was unable to comment inline on the following findings:

In packages/hash/realtime/src/index.ts:27-95, packages/hash/realtime/src/index.ts:27-82, packages/hash/realtime/src/index.ts:27-107:

Untrusted input concatinated with raw SQL query can result in SQL Injection.

Click a link below to tell your Security Team if this comment was:
👍 useful
👎 not useful (false positive)
🤔 confusing

Found by ajinabraham.njsscan.sql_injection.node_sqli_injection in Security Policy.

^{How do I suppress this?}

[nathggns]

I can confirm I've seen this issue and it's very annoying – thank you for aiming to fix it! Will take a look shortly.

[nathggns]

In a bad position in my local setup right now to review functionality, but the code looks great and it should solve the issue from what I can tell.