Conform more of the code base to strict null checking (#10147)

* Conform more of the code base to strict null checking

* More strict fixes

* More strict work

* Fix missing optional type

* Iterate

src/components/structures/auth/CompleteSecurity.tsx

@@ -57,7 +57,7 @@ export default class CompleteSecurity extends React.Component<IProps, IState> {
         store.stop();
     }
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const { phase, lostKeys } = this.state;
         let icon;
         let title;

src/components/structures/auth/E2eSetup.tsx

@@ -27,7 +27,7 @@ interface IProps {
 }
 
 export default class E2eSetup extends React.Component<IProps> {
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         return (
             <AuthPage>
                 <CompleteSecurityBody>

src/components/structures/auth/ForgotPassword.tsx

@@ -487,7 +487,7 @@ export default class ForgotPassword extends React.Component<Props, State> {
         );
     }
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         let resetPasswordJsx: JSX.Element;
 
         switch (this.state.phase) {

src/components/structures/auth/Login.tsx

@@ -563,7 +563,7 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
         );
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const loader =
             this.isBusy() && !this.state.busyLoggingIn ? (
                 <div className="mx_Login_loader">

src/components/structures/auth/Registration.tsx

@@ -573,7 +573,7 @@ export default class Registration extends React.Component<IProps, IState> {
         }
     }
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         let errorText;
         const err = this.state.errorText;
         if (err) {

src/components/structures/auth/SetupEncryptionBody.tsx

@@ -141,7 +141,7 @@ export default class SetupEncryptionBody extends React.Component<IProps, IState>
         this.props.onFinished();
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const { phase, lostKeys } = this.state;
 
         if (this.state.verificationRequest) {

src/components/structures/auth/SoftLogout.tsx

@@ -326,7 +326,7 @@ export default class SoftLogout extends React.Component<IProps, IState> {
         );
     }
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         return (
             <AuthPage>
                 <AuthHeader />