feat: remove deprecated code (#529)

BREAKING CHANGE: The RestrictedInput has been removed.
BREAKING CHANGE: The State component has been removed. Use React's [`useState`](https://reactjs.org/docs/hooks-reference.html#usestate) hook instead.
BREAKING CHANGE: The RadioButton and Switch components no longer accept the `onToggle` prop. Use the `onChange` prop instead.
BREAKING CHANGE: The Input and Textarea components no longer accept `*ClassName` props. Emotion 10 uses style objects instead of class names. Use the `*Styles` props instead.
BREAKING CHANGE: The Heading, SubHeading, Text, and Input components no longer accept the `element` prop. Emotion 10 introduced the ability to change the HTML element. Use the `as` prop instead.
BREAKING CHANGE: The SvgButton component has been renamed to IconButton.
BREAKING CHANGE: The SideNav component has been removed. Use the Sidebar component instead.
BREAKING CHANGE: The Picture component has been removed.
BREAKING CHANGE: The MaskedInput component has been removed. Use [`react-text-mask`](https://www.npmjs.com/package/react-text-mask) directly instead.
BREAKING CHANGE: The Markdown component has been removed. Use [`markdown-to-jsx`](https://github.com/probablyup/markdown-to-jsx) directly instead.
BREAKING CHANGE: The CreditCardDetails, CardNumberInput, NameOnCardInput, SecurityCodeInput, ExpiryDateInput, and the credit card utils have been removed. Use [SumUp's card widget](https://developer.sumup.com/docs/widgets-card-v2) instead.
BREAKING CHANGE: The ListView component has been renamed to CardList.
BREAKING CHANGE: The GlobalStyles component has been renamed to BaseStyles. It no longer accepts a `custom` prop. Use Emotion's [Global](https://emotion.sh/docs/globals) component instead.

package.json

@@ -129,22 +129,16 @@
   },
   "dependencies": {
     "@emotion/is-prop-valid": "^0.8.2",
-    "dom-helpers": "^5.1.0",
     "downshift": "^3.3.4",
-    "keycode": "^2.2.0",
     "lodash": "^4.17.11",
-    "markdown-to-jsx": "^6.9.3",
     "moment": "^2.24.0",
     "no-scroll": "^2.1.1",
     "polished": "^3.1.0",
     "prop-types": "^15.7.2",
-    "prop-types-exact": "^1.2.0",
     "react-dates": "^21.2.0",
-    "react-event-listener": "^0.6.6",
     "react-modal": "^3.8.1",
     "react-popper": "^1.3.3",
     "react-text-mask": "5.4.3",
-    "react-transition-group": "^4.3.0",
     "recompose": "^0.30.0",
     "text-mask-addons": "^3.8.0",
     "tiny-warning": "^1.0.3"