feat(utils): extract number utils to a separate package (#590)

* feat(utils): remove fp utils

The utils were mostly re-exports from `lodash/fp` — we might as well import them straight from there.

* feat(utils): remove dead code

* feat(utils): remove currency utils from exports

* feat(components): migrate CurrencyInput to use new intl package

BREAKING CHANGE:
The `currencyUtils` and `currencyAmountUtils` have been removed. Use
[@sumup/intl](https://www.npmjs.com/package/@sumup/intl) instead.

package.json

@@ -62,7 +62,7 @@
     "react-dates": "^21.2.0",
     "react-modal": "^3.8.1",
     "react-popper": "^1.3.3",
-    "react-text-mask": "5.4.3",
+    "react-text-mask": "^5.4.3",
     "recompose": "^0.30.0",
     "text-mask-addons": "^3.8.0",
     "tiny-warning": "^1.0.3",
@@ -97,6 +97,7 @@
     "@sumup/design-tokens": "^1.0.0-alpha.2",
     "@sumup/foundry": "^2.1.0",
     "@sumup/icons": "^1.0.0-canary.7",
+    "@sumup/intl": "^1.0.0",
     "@svgr/webpack": "^4.3.3",
     "@testing-library/dom": "^6.5.0",
     "@testing-library/jest-dom": "^4.1.0",
@@ -157,6 +158,7 @@
     "@emotion/stylis": "0.8.x",
     "@sumup/design-tokens": "1.x",
     "@sumup/icons": "1.x",
+    "@sumup/intl": "1.x",
     "emotion-theming": "10.x",
     "react": ">=16.8.0 < 17",
     "react-dom": ">=16.8.0 < 17"