Add support for --generate-function-body-options in Rust and C++ API

[NlightNFotis]

Description

Add support for the goto-instrument options --generate-function-body-options and --generate-function-body in the Rust and C++ API.

The end result should be facilitating an interaction with the API that achieves a similar result to the following goto-instrument invocation: goto-instrument --generate-function-body-options assert-false-assume-false --generate-function-body ".*" --drop-unused-functions b_harness.out b_harness.out

Context

[This is to track items outlined in #7042 that are missing to make the C++ and Rust API more useful]