Avoid creating temporary arrays

Motivation:

When we only want the first byte, rather than create temporary
intermediate arrays we can just ask NIO to give us the first byte. This
avoids unnecessary allocations.

Modifications:

- Replace `readBytes(length: 1).first` with `readInteger(as:
  UInt8.self)`

Results:

11% performance improvement in load testing due to reduced allocator
pressure on the hot path.

Author: Lukasa

Sources/RediStack/RESP/RESPTranslator.swift

@@ -123,8 +123,8 @@ extension RESPTranslator {
     /// - Returns: The parsed `RESPValue` or nil.
     public func parseBytes(from buffer: inout ByteBuffer) throws -> RESPValue? {
         var copy = buffer
-        
-        guard let token = copy.readBytes(length: 1)?.first else { return nil }
+
+        guard let token = copy.readInteger(as: UInt8.self) else { return nil }
 
         let result: RESPValue?
         switch token {