Add Presto sidecar process type

[tdcmeehan]

To support RFC-0003, a new process type is introduced, the sidecar. The purpose of the sidecar is to provide a series of endpoints to inform the Presto coordinator of the capabilities of the underlying workers, and to provide a mechanism for the coordinator to use that functionality. In order to support constant folding without relying on coincidental implementations of user-defined functions in Java, for example, either expressions or functions must be executed in C++, and the sidecar can support this. Likewise, the sidecar can be used to inform the coordinator of the function registry and worker-level session properties.

This issue is to add support for the Presto sidecar. It will be implemented as a new process type in Presto, alongside the worker, coordinator, and resource manager. The sidecar will announce itself to the discovery service, as other services do. The coordinator will have some small changes made to change its behavior when the sidecar is expected but not running, for example, it may queue or fail queries.

The sidecar will be externally managed, as with other process types in Presto. It is expected that external orchestration will ensure the sidecar is running. Eventually, the Presto Helm chart will be updated for native clusters to utilize the sidecar, and external users must eventually opt to use the sidecar.

The code for the sidecar will be in the existing presto-native-execution module and will share code with the C++ worker process developed there.