feat: add env variable for enable key manager service (#5442)

Co-authored-by: dracarys18 <karthikey.hegde@juspay.in>

crates/common_utils/src/types/keymanager.rs

@@ -23,6 +23,7 @@ use crate::{
 
 #[derive(Debug)]
 pub struct KeyManagerState {
+    pub enabled: Option<bool>,
     pub url: String,
     pub client_idle_timeout: Option<u64>,
     #[cfg(feature = "keymanager_mtls")]