Add --long-timeouts-multiplier CLI flag (#7047)

Adds the `--long-timeouts-multiplier` flag.
Allows granular control for VC timeouts which has proved useful in Holesky.

validator_client/src/config.rs

@@ -49,6 +49,8 @@ pub struct Config {
     pub init_slashing_protection: bool,
     /// If true, use longer timeouts for requests made to the beacon node.
     pub use_long_timeouts: bool,
+    /// Multiplier to use for long timeouts.
+    pub long_timeouts_multiplier: u32,
     /// Graffiti to be inserted everytime we create a block.
     pub graffiti: Option<Graffiti>,
     /// Graffiti file to load per validator graffitis.
@@ -112,6 +114,7 @@ impl Default for Config {
             disable_auto_discover: false,
             init_slashing_protection: false,
             use_long_timeouts: false,
+            long_timeouts_multiplier: 1,
             graffiti: None,
             graffiti_file: None,
             http_api: <_>::default(),
@@ -196,6 +199,7 @@ impl Config {
         config.disable_auto_discover = validator_client_config.disable_auto_discover;
         config.init_slashing_protection = validator_client_config.init_slashing_protection;
         config.use_long_timeouts = validator_client_config.use_long_timeouts;
+        config.long_timeouts_multiplier = validator_client_config.long_timeouts_multiplier;
 
         if let Some(graffiti_file_path) = validator_client_config.graffiti_file.as_ref() {
             let mut graffiti_file = GraffitiFile::new(graffiti_file_path.into());