fix: clap CLI definitions and manpage generation

- add #[group(skip)] to all Parser-derived structs
- fix conflicts_with and arg definitions for correct CLI behavior
- refactor bin entry points to support manpage generation

core/src/util/rpc.rs

@@ -22,6 +22,7 @@ pub fn util<C: Context>() -> ParentHandler<C> {
 }
 
 #[derive(Debug, Deserialize, Serialize, Parser)]
+#[group(skip)]
 pub struct B3sumParams {
     #[arg(long = "no-mmap", action = clap::ArgAction::SetFalse, help = "help.arg.no-mmap")]
     allow_mmap: bool,