Feat: HttpReader (#1733)

* The start of implementing http_reader, issue #1644

* structure done

* v1 of http_reader

* first http_header poc

* Add AsyncSeek trait

* remove import

* move import

* fix typo

* add error checking for async seek

* fix handling of positions

* rename variables

* Update backend/src/util/http_reader.rs

Co-authored-by: Aiden McClelland <3732071+dr-bonez@users.noreply.github.com>

* clean up work

* improve error handling, and change if statement.

Co-authored-by: Stephen Chavez <stephen@start9labs.com>
Co-authored-by: Aiden McClelland <3732071+dr-bonez@users.noreply.github.com>

backend/src/util/mod.rs

@@ -25,6 +25,7 @@ use crate::shutdown::Shutdown;
 use crate::{Error, ErrorKind, ResultExt as _};
 pub mod config;
 pub mod io;
+pub mod http_reader;
 pub mod logger;
 pub mod serde;