[docs] Add doc for CMake flag PRESTO_ENABLE_REMOTE_FUNCTIONS

[steveburnett]

The documentation for Presto C++ Remote Function Execution does not mention the CMake flag PRESTO_ENABLE_REMOTE_FUNCTIONS that enables this functionality.

The Presto C++ JWT authentication support doc also does not mention a needed CMake flag.

Other Presto C++ CMake flags in CMakeLists.txt may need documentation. While some of these - such as the JWT flag, and PRESTO_STATS_REPORTER_TYPE=PROMETHEUS - are documented in the presto-native-execution README, not all of the CMake flags in CMakeLists.txt are documented in the presto-native-execution README.

Expected Behavior or Use Case

PRESTO_ENABLE_REMOTE_FUNCTIONS should be documented somewhere. Other CMake flags may also need to be documented.

Presto Component, Service, or Connector

Documentation.

Possible Implementation

• Add documentation for PRESTO_ENABLE_REMOTE_FUNCTIONS to the presto-native-execution README.
• Add a mention to Presto C++ Remote Function Execution that building Presto C++ with CMake flag PRESTO_ENABLE_REMOTE_FUNCTIONS is required to enable these, with a link to the presto-native-execution README.

Further work to consider, maybe to be addressed in a separate PR from the above:

• Identify undocumented Presto C++ CMake flags in CMakeLists.txt.
• Add documentation for the identified Presto C++ CMake flags to the presto-native-execution README.
• Add mentions of the identified Presto C++ CMake flags to the Presto C++ doc as needed.

Context

If Presto C++ is built without the CMake flag PRESTO_ENABLE_REMOTE_FUNCTIONS, the Presto C++ Remote Function Execution functions are not available. The Presto C++ Remote Function Execution does not mention this so readers of Presto C++ Remote Function Execution may not realize why, or how to enable these functions.

[steveburnett]

@majetideepak, @aditi-pandit, please review and provide feedback, changes, and edits, and invite others to do the same, as you feel appropriate. Thanks!

[tdcmeehan]

I think in general, we should list this as a limitation of Prestissimo--unlike Presto, in Prestissimo you must build the entire C++ executable with the flag relevant to your organization. i.e. what was once a runtime toggle has become a build time toggle.

[majetideepak]

@tdcmeehan Most of these are both runtime and build toggle. We keep build toggles to save on build time and minimize dependencies.

[tdcmeehan]

@majetideepak got it. Then does it make sense to document these in user facing documentation, or should we just leave it in the README?

[majetideepak]

I like the arrow approach. We should add a document page just for building. We specify all the build flags here. https://arrow.apache.org/docs/developers/cpp/building.html

We then specify the runtime configuration along with the feature documentation.

[majetideepak]

I don't think README is the right spot for any documentation. We can link to the building.html from the README.

[tdcmeehan]

@majetideepak thinking of our ideal end state, do we expect typical users of Prestissimo to build it? Arrow, as a library, has this expectation, but do we expect that of Prestissimo users?

[majetideepak]

@tdcmeehan I expect data engineers to want to know how to build. DuckDB https://duckdb.org/docs/dev/building/build_instructions.html has a page as well.