feat: add a generic parameter to error::Result<T, E=Error> (with default value)

Author: gmoshkin

CHANGELOG.md

@@ -5,7 +5,12 @@
 ### Added
 - `network::client::tcp::TcpStream` not supports async connection, provided with `connect_async` and `connect_timeout_async` methods
 
-### Fixes
+### Changed
+- `error::Result` type alias now has another generic parameter E, which defaults
+  to `tarantool::error::Error`, but allows this type alias to be used as a drop
+  in replacement from `std::result::Result`.
+
+### Fixed
 - `network::client::tcp::TcpStream` does not close underlying fd anymore. Now fd will be closed only when the last copy of tcp stream is dropped.
 
 ### Deprecated

tarantool/src/error.rs

@@ -33,7 +33,7 @@ use crate::transaction::TransactionError;
 use crate::util::to_cstring_lossy;
 
 /// A specialized [`Result`] type for the crate
-pub type Result<T> = std::result::Result<T, Error>;
+pub type Result<T, E = Error> = std::result::Result<T, E>;
 
 pub type TimeoutError<E> = crate::fiber::r#async::timeout::Error<E>;