feat: add &str utf8 conv error to LibError enum

src/error.rs

@@ -4,6 +4,7 @@ pub enum LibError {
     InvalidUrlError(InvalidUrl),
     StatusOutOfRange(u8),
     MessageNotUtf8(std::string::FromUtf8Error),
+    BodyNotUtf8(std::str::Utf8Error),
     InvalidMime(mime::FromStrError),
 }
 
@@ -42,6 +43,13 @@ impl From<std::string::FromUtf8Error> for LibError {
     }
 }
 
+impl From<std::str::Utf8Error> for LibError {
+    #[inline]
+    fn from(err: std::str::Utf8Error) -> Self {
+        Self::BodyNotUtf8(err)
+    }
+}
+
 impl From<mime::FromStrError> for LibError {
     #[inline]
     fn from(err: mime::FromStrError) -> Self {