Extracting the Error impl from the monolith eth2 (#7878)

Currently the `eth2` crate lib file is a large monolith of almost 3000 lines of code. As part of the bosun migration we are trying to increase code readability and modularity in the lighthouse crates initially, which then can be transferred to bosun


Co-Authored-By: hopinheimer <knmanas6@gmail.com>

Co-Authored-By: hopinheimer <48147533+hopinheimer@users.noreply.github.com>

common/eth2/src/lighthouse_vc/http_client.rs

@@ -1,5 +1,5 @@
 use super::types::*;
-use crate::Error;
+use crate::{Error, success_or_error};
 use reqwest::{
     IntoUrl,
     header::{HeaderMap, HeaderValue},
@@ -145,7 +145,7 @@ impl ValidatorClientHttpClient {
             .send()
             .await
             .map_err(Error::from)?;
-        ok_or_error(response).await
+        success_or_error(response).await
     }
 
     /// Perform a HTTP DELETE request, returning the `Response` for further processing.
@@ -157,7 +157,7 @@ impl ValidatorClientHttpClient {
             .send()
             .await
             .map_err(Error::from)?;
-        ok_or_error(response).await
+        success_or_error(response).await
     }
 
     async fn get<T: DeserializeOwned, U: IntoUrl>(&self, url: U) -> Result<T, Error> {
@@ -218,7 +218,7 @@ impl ValidatorClientHttpClient {
             .send()
             .await
             .map_err(Error::from)?;
-        ok_or_error(response).await
+        success_or_error(response).await
     }
 
     async fn post<T: Serialize, U: IntoUrl, V: DeserializeOwned>(
@@ -250,7 +250,7 @@ impl ValidatorClientHttpClient {
             .send()
             .await
             .map_err(Error::from)?;
-        ok_or_error(response).await?;
+        success_or_error(response).await?;
         Ok(())
     }
 
@@ -268,7 +268,7 @@ impl ValidatorClientHttpClient {
             .send()
             .await
             .map_err(Error::from)?;
-        ok_or_error(response).await
+        success_or_error(response).await
     }
 
     /// Perform a HTTP DELETE request.
@@ -681,20 +681,3 @@ impl ValidatorClientHttpClient {
         self.delete(url).await
     }
 }
-
-/// Returns `Ok(response)` if the response is a `200 OK` response or a
-/// `202 Accepted` response. Otherwise, creates an appropriate error message.
-async fn ok_or_error(response: Response) -> Result<Response, Error> {
-    let status = response.status();
-
-    if status == StatusCode::OK
-        || status == StatusCode::ACCEPTED
-        || status == StatusCode::NO_CONTENT
-    {
-        Ok(response)
-    } else if let Ok(message) = response.json().await {
-        Err(Error::ServerMessage(message))
-    } else {
-        Err(Error::StatusCode(status))
-    }
-}