Create the AccountManagementError enum

Otherwise it forces dependant crates to add serde_urlencoded as a dependency
just to be able to forward the error type.

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

crates/oidc-client/src/error.rs

@@ -64,6 +64,9 @@ pub enum Error {
 
     /// An error occurred introspecting a token.
     Introspection(#[from] IntrospectionError),
+
+    /// An error occurred building the account management URL.
+    AccountManagement(#[from] AccountManagementError),
 }
 
 /// All possible errors when fetching provider metadata.
@@ -703,3 +706,11 @@ pub enum CredentialsError {
     #[error(transparent)]
     Custom(BoxError),
 }
+
+/// All errors that can occur when building the account management URL.
+#[derive(Debug, Error)]
+pub enum AccountManagementError {
+    /// An error occurred serializing the parameters.
+    #[error(transparent)]
+    UrlEncoded(#[from] serde_urlencoded::ser::Error),
+}