Function generate_rust_indices_from_defs

pub fn generate_rust_indices_from_defs(params: &[ParamDef]) -> String

Generate Rust parameter index constants from a const array of ParamDefs.

Output example:

pub const PARAM_GAIN: usize = 0;
pub const PARAM_PAN: usize = 1;
pub const PARAM_COUNT: usize = 2;