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/async-components/views/dialogs/eventindex/ManageEventIndexDialog.tsx

@@ -143,7 +143,7 @@ export default class ManageEventIndexDialog extends React.Component<IProps, ISta
         SettingsStore.setValue("crawlerSleepTime", null, SettingLevel.DEVICE, e.target.value);
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const brand = SdkConfig.get().brand;
 
         let crawlerState;

src/async-components/views/dialogs/security/CreateKeyBackupDialog.tsx

@@ -459,7 +459,7 @@ export default class CreateKeyBackupDialog extends React.PureComponent<IProps, I
         }
     }
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         let content;
         if (this.state.error) {
             content = (

src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx

@@ -842,7 +842,7 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
         }
     }
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         let content;
         if (this.state.error) {
             content = (

src/async-components/views/dialogs/security/ExportE2eKeysDialog.tsx

@@ -127,7 +127,7 @@ export default class ExportE2eKeysDialog extends React.Component<IProps, IState>
         } as Pick<IState, AnyPassphrase>);
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const disableForm = this.state.phase === Phase.Exporting;
 
         return (

src/async-components/views/dialogs/security/ImportE2eKeysDialog.tsx

@@ -127,7 +127,7 @@ export default class ImportE2eKeysDialog extends React.Component<IProps, IState>
         return false;
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const disableForm = this.state.phase !== Phase.Edit;
 
         return (

src/async-components/views/dialogs/security/NewRecoveryMethodDialog.tsx

@@ -48,13 +48,13 @@ export default class NewRecoveryMethodDialog extends React.PureComponent<IProps>
             {
                 onFinished: this.props.onFinished,
             },
-            null,
+            undefined,
             /* priority = */ false,
             /* static = */ true,
         );
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const title = <span className="mx_KeyBackupFailedDialog_title">{_t("New Recovery Method")}</span>;
 
         const newMethodDetected = <p>{_t("A new Security Phrase and key for Secure Messages have been detected.")}</p>;

src/async-components/views/dialogs/security/RecoveryMethodRemovedDialog.tsx

@@ -37,14 +37,14 @@ export default class RecoveryMethodRemovedDialog extends React.PureComponent<IPr
         this.props.onFinished();
         Modal.createDialogAsync(
             import("./CreateKeyBackupDialog") as unknown as Promise<ComponentType<{}>>,
-            null,
+            undefined,
             null,
             /* priority = */ false,
             /* static = */ true,
         );
     };
 
-    public render(): JSX.Element {
+    public render(): React.ReactNode {
         const title = <span className="mx_KeyBackupFailedDialog_title">{_t("Recovery Method Removed")}</span>;
 
         return (