client-api: Add support for local user erasure

According to MSC4025

crates/ruma-client-api/CHANGELOG.md

@@ -24,6 +24,8 @@ Improvements:
 - Add deprecated `address` and `medium` 3PID fields for `m.login.password`
   login type.
 - Add optional cookie field to `session::sso_login*::v3` responses.
+- Add support for local user erasure to `account::deactivate::v3::Request`,
+  according to MSC4025.
 
 # 0.17.4
 

crates/ruma-client-api/src/account/deactivate.rs

@@ -39,6 +39,13 @@ pub mod v3 {
         /// identifier.
         #[serde(skip_serializing_if = "Option::is_none")]
         pub id_server: Option<String>,
+
+        /// Whether the user would like their content to be erased as much as possible from the
+        /// server.
+        ///
+        /// Defaults to `false`.
+        #[serde(default, skip_serializing_if = "ruma_common::serde::is_default")]
+        pub erase: bool,
     }
 
     /// Response type for the `deactivate` endpoint.