docs(rpc): correct PRC typo in docs and comments (#5130)

### What problem does this PR solve?

Problem Summary:
Several RPC docs and comments use `PRC` instead of `RPC`, which is a
typo and can confuse readers.

### What is changed and how it works?

What changed:
- replace `PRC` with `RPC` in `rpc/README.md`
- replace the same typo in `rpc/src/module/chain.rs`
- update `rpc/src/server.rs` to refer to the old RPC error response

### Related changes

- PR to update `owner/repo`: N/A
- Need to cherry-pick to the release branch: N/A

### Check List

Tests
- No code

Side effects
- None

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: zhangsoledad <787953403@qq.com>

Author: 3 people

rpc/README.md

@@ -512,7 +512,7 @@ The RPC returns the block when `block_number` is less than or equal to the tip b
 number returned by [`get_tip_block_number`](#tymethod.get_tip_block_number) and returns
 null otherwise.
 
-Because of [chain reorganization](#chain-reorganization), the PRC may return null or even
+Because of [chain reorganization](#chain-reorganization), the RPC may return null or even
 different blocks in different invocations with the same `block_number`.
 
 When `verbosity` is 2, it returns a JSON object as the `result`. See `BlockView` for the
@@ -725,7 +725,7 @@ The RPC returns the block header when `block_number` is less than or equal to th
 number returned by [`get_tip_block_number`](#tymethod.get_tip_block_number) and returns
 null otherwise.
 
-Because of [chain reorganization](#chain-reorganization), the PRC may return null or even
+Because of [chain reorganization](#chain-reorganization), the RPC may return null or even
 different block headers in different invocations with the same `block_number`.
 
 When `verbosity` is 1, it returns a JSON object as the `result`. See `HeaderView` for the
@@ -990,7 +990,7 @@ The RPC returns the block hash when `block_number` is less than or equal to the
 number returned by [`get_tip_block_number`](#tymethod.get_tip_block_number) and returns
 null otherwise.
 
-Because of [chain reorganization](#chain-reorganization), the PRC may return null or even
+Because of [chain reorganization](#chain-reorganization), the RPC may return null or even
 different block hashes in different invocations with the same `block_number`.
 
 ###### Examples

rpc/src/module/chain.rs

@@ -201,7 +201,7 @@ pub trait ChainRpc {
     /// number returned by [`get_tip_block_number`](#tymethod.get_tip_block_number) and returns
     /// null otherwise.
     ///
-    /// Because of [chain reorganization](#chain-reorganization), the PRC may return null or even
+    /// Because of [chain reorganization](#chain-reorganization), the RPC may return null or even
     /// different blocks in different invocations with the same `block_number`.
     ///
     /// When `verbosity` is 2, it returns a JSON object as the `result`. See `BlockView` for the
@@ -413,7 +413,7 @@ pub trait ChainRpc {
     /// number returned by [`get_tip_block_number`](#tymethod.get_tip_block_number) and returns
     /// null otherwise.
     ///
-    /// Because of [chain reorganization](#chain-reorganization), the PRC may return null or even
+    /// Because of [chain reorganization](#chain-reorganization), the RPC may return null or even
     /// different block headers in different invocations with the same `block_number`.
     ///
     /// When `verbosity` is 1, it returns a JSON object as the `result`. See `HeaderView` for the
@@ -674,7 +674,7 @@ pub trait ChainRpc {
     /// number returned by [`get_tip_block_number`](#tymethod.get_tip_block_number) and returns
     /// null otherwise.
     ///
-    /// Because of [chain reorganization](#chain-reorganization), the PRC may return null or even
+    /// Because of [chain reorganization](#chain-reorganization), the RPC may return null or even
     /// different block hashes in different invocations with the same `block_number`.
     ///
     /// ## Examples

rpc/src/server.rs

@@ -204,7 +204,7 @@ async fn ping_handler() -> impl IntoResponse {
     "pong"
 }
 
-/// used for compatible with old PRC error response for GET
+/// Used for compatibility with the old RPC error response for GET requests.
 async fn get_error_handler() -> impl IntoResponse {
     (
         StatusCode::METHOD_NOT_ALLOWED,