convert to emotion

Summary:
My benchmarks have shown react-emotion to be faster than the current implementation of `styled`. For this reason, I am converting all styling to [emotion](https://emotion.sh).

Benchmark results:
{F136839093}

The syntax is very similar between the two libraries. The main difference is that emotion only allows a single function for the whole style attribute, whereas the old implementation had functions for every style-attirbute.

Before:
```
{
  color: props => props.color,
  fontSize: props => props.size,
}
```

After:
```
props => ({
  color: props.color,
  fontSize: props.size,
})
```

Reviewed By: jknoxville

Differential Revision: D9479893

fbshipit-source-id: 2c39e4618f7e52ceacb67bbec8ae26114025723f

src/ui/components/console.js

@@ -15,6 +15,7 @@ import {
   Input,
   View,
 } from '../index';
+import styled from '../styled/index';
 import type {TableBodyRow, TableRows} from 'sonar';
 import type {PluginClient} from '../../plugin';
 
@@ -50,7 +51,7 @@ class ConsoleError extends Component<{
   error: Error | string | void,
   className?: string,
 }> {
-  static Container = CodeBlock.extends({
+  static Container = styled(CodeBlock)({
     backgroundColor: colors.redTint,
     color: colors.red,
     overflow: 'auto',
@@ -81,11 +82,11 @@ export class Console extends Component<Props, State> {
     },
   };
 
-  static Window = FlexColumn.extends({
+  static Window = styled(FlexColumn)({
     padding: '15px',
     flexGrow: 1,
   });
-  static Input = Input.extends({
+  static Input = styled(Input)({
     width: '100%',
   });