fix: possible exception in request_context (#5784)

Description
---
Fixed possible exception in `pub struct RequestContext` that could occur
when splitting the request and reply channel in `pub fn split`

Motivation and Context
---
The code should not be allowed to panic in use in the wrong context.

How Has This Been Tested?
---
Unit tests

What process can a PR reviewer use to test or verify this change?
---
Code walk through

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Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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---------

Co-authored-by: SW van Heerden <swvheerden@gmail.com>

base_layer/service_framework/src/lib.rs

@@ -52,7 +52,7 @@
 //!         // At the same time receive the request and reply
 //!         async move {
 //!             let req_context = receiver.next().await.unwrap();
-//!             let msg = req_context.request().unwrap().clone();
+//!             let msg = req_context.request().clone();
 //!             req_context.reply(msg.to_uppercase());
 //!         }
 //!     );

base_layer/service_framework/src/reply_channel.rs

@@ -131,37 +131,25 @@ impl<T> Future for TransportResponseFuture<T> {
 /// request.
 pub struct RequestContext<TReq, TResp> {
     reply_tx: oneshot::Sender<TResp>,
-    request: Option<TReq>,
+    request: TReq,
 }
 
 impl<TReq, TResp> RequestContext<TReq, TResp> {
     /// Create a new RequestContect
     pub fn new(request: TReq, reply_tx: oneshot::Sender<TResp>) -> Self {
-        Self {
-            request: Some(request),
-            reply_tx,
-        }
+        Self { request, reply_tx }
     }
 
     /// Return a reference to the request object. None is returned after take_request has
     /// been called.
-    pub fn request(&self) -> Option<&TReq> {
-        self.request.as_ref()
-    }
-
-    /// Take ownership of the request object, if ownership has not already been taken,
-    /// otherwise None is returned.
-    pub fn take_request(&mut self) -> Option<TReq> {
-        self.request.take()
+    pub fn request(&self) -> &TReq {
+        &self.request
     }
 
     /// Consume this object and return it's parts. Namely, the request object and
     /// the reply oneshot channel.
     pub fn split(self) -> (TReq, oneshot::Sender<TResp>) {
-        (
-            self.request.expect("RequestContext must be initialized with a request"),
-            self.reply_tx,
-        )
+        (self.request, self.reply_tx)
     }
 
     /// Sends a reply to the caller