Function build_options_string 

pub(crate) fn build_options_string(
    options: &BTreeMap<String, String>,
) -> Option<String>

Build the inner value of the libpq options connection parameter from a profile’s options map.

Produces a space-separated string of -c key=value tokens in sorted-key order, with each value inner-escaped per escape_options_value. Returns None when the map is empty so the caller can omit the fragment.