refactor: revamp update mechanism of session & kernel status

[fregataa]

resolves #2266

Changes

Update kernel status to {PREPARING,PULLING,RUNNING,TERMINATING}

1. When a manager consumes Kernel{PREPARING,PULLING,RUNNING,TERMINATING}Event, set the status of kernel to the given status and save session_id of the kernel to Redis. - SADD command is used here
2. Among managers, update_session_status() task is triggered by a global timer. The task fetches session_ids from Redis that saved in step 2.
3. The task fetches session rows & binding kernel rows from DB and calculates the session status.
4. Update the calculated session status to DB.

Update kernel status to else status ...

Just set the status of session & kernels to the given status.

Checklist: (if applicable)

• Milestone metadata specifying the target backport version
• Mention to the original issue
• API server-client counterparts (e.g., manager API -> client SDK)

[fregataa]

• feat: Add session status checker API #2312 : 2 dependent PRs (#2646 , #2836 )
• refactor: revamp update mechanism of session & kernel status #2311 👈
• feat: Add interface that update session and kernel status #2581
• main

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