CB-17544 Create separate machine user and access key for monitoring.

[foldik]

See detailed description in the commit message.

[foldik]

I double checked the UMS code and they delete roles and access keys after the machine user is deleted as they say in the official documentation.

[oleewere]

I double checked the UMS code and they delete roles and access keys after the machine user is deleted as they say in the official documentation.

i meant the UMS cleanup job, but i have missed this in the line: name.startsWith("datalake-monitoring"), so it's fine, we are good

[foldik]

@lacikaaa I fixed the change based on your suggestions. I created a separate ticket for the secret migration into different table since it would be a bigger effort.