Update call lobby UI to match new designs

ts/components/Button.tsx

@@ -1,7 +1,7 @@
 // Copyright 2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-import React, { MouseEventHandler, ReactNode } from 'react';
+import React, { CSSProperties, MouseEventHandler, ReactNode } from 'react';
 import classNames from 'classnames';
 
 import { assert } from '../util/assert';
@@ -17,12 +17,15 @@ export enum ButtonVariant {
   SecondaryAffirmative,
   SecondaryDestructive,
   Destructive,
+  Calling,
 }
 
 type PropsType = {
   className?: string;
   disabled?: boolean;
   size?: ButtonSize;
+  style?: CSSProperties;
+  tabIndex?: number;
   variant?: ButtonVariant;
 } & (
   | {
@@ -64,6 +67,7 @@ const VARIANT_CLASS_NAMES = new Map<ButtonVariant, string>([
     'module-Button--secondary module-Button--secondary--destructive',
   ],
   [ButtonVariant.Destructive, 'module-Button--destructive'],
+  [ButtonVariant.Calling, 'module-Button--calling'],
 ]);
 
 export const Button = React.forwardRef<HTMLButtonElement, PropsType>(
@@ -73,6 +77,8 @@ export const Button = React.forwardRef<HTMLButtonElement, PropsType>(
       className,
       disabled = false,
       size = ButtonSize.Medium,
+      style,
+      tabIndex,
       variant = ButtonVariant.Primary,
     } = props;
     const ariaLabel = props['aria-label'];
@@ -105,6 +111,8 @@ export const Button = React.forwardRef<HTMLButtonElement, PropsType>(
         disabled={disabled}
         onClick={onClick}
         ref={ref}
+        style={style}
+        tabIndex={tabIndex}
         // The `type` should either be "button" or "submit", which is effectively static.
         // eslint-disable-next-line react/button-has-type
         type={type}