Preparations for React 18 (#12860)

* Add missing types

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Eagerly add `children` to props in prep for React 18

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Avoid assuming that setState immediately sets `this.state` values

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Add missing context declaration

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Fix UserFriendlyError types to work with React 18

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

---------

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/structures/auth/Registration.tsx

@@ -248,15 +248,20 @@ export default class Registration extends React.Component<IProps, IState> {
             logger.error("Failed to get login flows to check for SSO support", e);
         }
 
-        this.setState(({ flows }) => ({
-            matrixClient: cli,
-            ssoFlow,
-            oidcNativeFlow,
-            // if we are using oidc native we won't continue with flow discovery on HS
-            // so set an empty array to indicate flows are no longer loading
-            flows: oidcNativeFlow ? [] : flows,
-            busy: false,
-        }));
+        await new Promise<void>((resolve) => {
+            this.setState(
+                ({ flows }) => ({
+                    matrixClient: cli,
+                    ssoFlow,
+                    oidcNativeFlow,
+                    // if we are using oidc native we won't continue with flow discovery on HS
+                    // so set an empty array to indicate flows are no longer loading
+                    flows: oidcNativeFlow ? [] : flows,
+                    busy: false,
+                }),
+                resolve,
+            );
+        });
 
         // don't need to check with homeserver for login flows
         // since we are going to use OIDC native flow