Add option to enable worker graceful shutdown

[sdaberdaku]

In this PR I have automated the process of enabling the Worker Graceful Shutdown feature.

Enabling the option will:

• Add a preStop lifecycle event to all worker Pods;
• Set the shutdown.grace-period configuration property to gracePeriod;
• Configure the workers' accessControl since the default system access control does not allow graceful shutdowns.

I also added a test to check if the graceful shutdown endpoint can be successfully called on the worker Pods.

Fixes #189

[nineinchnick]

This looks good, but I have some comments about making it even more robust, and not allowing users to make configuration mistakes.

[sdaberdaku]

Hello @nineinchnick,

Thank you so much for finding the time to review this PR!
I will try to implement all the required changes, hopefully during this week and I will let you know then they are ready.

[nineinchnick]

Thanks! No rush and we can always chat on the Trino slack if anything is not clear enough

[sdaberdaku]

Dear @nineinchnick,

I have addressed all your comments.

Regarding the test implementation, I considered using a long-running query; however, I was uncertain about its appropriateness as it seemed more like a Trino test than a Helm Chart test. Ultimately, my testing approach involves deleting a worker pod using kubectl and verifying that the logs of the affected pod contain the "Shutdown requested" string. This method effectively tests both the worker's authorization and the lifecycle configuration.

Looking forward to your feedback!

[nineinchnick]

This is looking great now, thanks! Resolve the conflict and we can merge this.

[sdaberdaku]

I rebased and addressed your last comment. Should be ready now!

[nineinchnick]

One last nitpick to get better docs.