Add react-i18next for multi-language support (#917)

This is a rough start on adding react-i18next. I'll be working on adding
more translatable strings and translations in the coming days. I'm going
to need to wrap class components in HOCs, so let me know if there's
something I should be fixing before doing that. I'm thinking now to keep
the exported class names exactly the same, and rename the existing
classes by prefixing an `I` (for internal). For example:

```
export default class AppToolbar ...
```

becomes

```
class IAppToolbar ...
const AppToolbar = withTranslation()(IAppToolbar);
export default AppToolbar;
```

I'll be able to contribute Japanese strings (I've talked to a couple
people on my team and they'll be happy to help as well), so that's the
language I decided to go with in this PR.

Closes #746

---------

Co-authored-by: Ko Nagase <nagase@georepublic.co.jp>
Co-authored-by: Harel M <harel.mazor@gmail.com>

src/components/App.tsx

@@ -24,7 +24,6 @@ import ModalExport from './ModalExport'
 import ModalSources from './ModalSources'
 import ModalOpen from './ModalOpen'
 import ModalShortcuts from './ModalShortcuts'
-import ModalSurvey from './ModalSurvey'
 import ModalDebug from './ModalDebug'
 
 import {downloadGlyphsMetadata, downloadSpriteMetadata} from '../libs/metadata'
@@ -128,7 +127,6 @@ type AppState = {
     open: boolean
     shortcuts: boolean
     export: boolean
-    survey: boolean
     debug: boolean
   }
 }
@@ -137,7 +135,6 @@ export default class App extends React.Component<any, AppState> {
   revisionStore: RevisionStore;
   styleStore: StyleStore | ApiStyleStore;
   layerWatcher: LayerWatcher;
-  shortcutEl: ModalShortcuts | null = null;
 
   constructor(props: any) {
     super(props)
@@ -277,7 +274,6 @@ export default class App extends React.Component<any, AppState> {
         shortcuts: false,
         export: false,
         // TODO: Disabled for now, this should be opened on the Nth visit to the editor
-        survey: false,
         debug: false,
       },
       maplibreGlDebugOptions: {
@@ -839,10 +835,6 @@ export default class App extends React.Component<any, AppState> {
   }
 
   setModal(modalName: keyof AppState["isOpen"], value: boolean) {
-    if(modalName === 'survey' && value === false) {
-      localStorage.setItem('survey', '');
-    }
-
     this.setState({
       isOpen: {
         ...this.state.isOpen,
@@ -942,7 +934,6 @@ export default class App extends React.Component<any, AppState> {
         mapView={this.state.mapView}
       />
       <ModalShortcuts
-        ref={(el) => this.shortcutEl = el}
         isOpen={this.state.isOpen.shortcuts}
         onOpenToggle={this.toggleModal.bind(this, 'shortcuts')}
       />
@@ -970,10 +961,6 @@ export default class App extends React.Component<any, AppState> {
         isOpen={this.state.isOpen.sources}
         onOpenToggle={this.toggleModal.bind(this, 'sources')}
       />
-      <ModalSurvey
-        isOpen={this.state.isOpen.survey}
-        onOpenToggle={this.toggleModal.bind(this, 'survey')}
-      />
     </div>
 
     return <AppLayout