Add new session verification details dialog

This gives more info on the session you're about to verify, including device
name and ID.

Fixes https://github.com/vector-im/riot-web/issues/11977

src/components/views/elements/DialogButtons.js

@@ -83,7 +83,7 @@ export default createReactClass({
                 // primary in the DOM so will get form submissions unless we make it not a submit.
                 type="button"
                 onClick={this._onCancelClick}
-		className={this.props.cancelButtonClass}
+                className={this.props.cancelButtonClass}
                 disabled={this.props.disabled}
             >
                 { this.props.cancelButton || _t("Cancel") }