Migration of jsx files to tsx 2 (#850)

This is to continue the work of migrating all the jsx files into tsx
files.
The MO is basically described here: #848.

About 7 files to go...

src/components/AppLayout.tsx

@@ -0,0 +1,46 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+import ScrollContainer from './ScrollContainer'
+
+type AppLayoutProps = {
+  toolbar: React.ReactElement
+  layerList: React.ReactElement
+  layerEditor?: React.ReactElement
+  map: React.ReactElement
+  bottom?: React.ReactElement
+  modals?: React.ReactNode
+};
+
+class AppLayout extends React.Component<AppLayoutProps> {
+  static childContextTypes = {
+    reactIconBase: PropTypes.object
+  }
+
+  getChildContext() {
+    return {
+      reactIconBase: { size: 14 }
+    }
+  }
+
+  render() {
+    return <div className="maputnik-layout">
+      {this.props.toolbar}
+      <div className="maputnik-layout-list">
+        {this.props.layerList}
+      </div>
+      <div className="maputnik-layout-drawer">
+        <ScrollContainer>
+          {this.props.layerEditor}
+        </ScrollContainer>
+      </div>
+      {this.props.map}
+      {this.props.bottom && <div className="maputnik-layout-bottom">
+          {this.props.bottom}
+        </div>
+      }
+      {this.props.modals}
+    </div>
+  }
+}
+
+export default AppLayout