MM-33599 Add support for data uri icons for slash commands (#5393)

* Add support for data uri icons for slash commands

* Address PR feedback

* Fix lint

* Use only one style for http and data icons

package.json

@@ -19,6 +19,7 @@
     "@rudderstack/rudder-sdk-react-native": "1.0.12",
     "@sentry/react-native": "2.6.0",
     "analytics-react-native": "1.2.0",
+    "base-64": "1.0.0",
     "commonmark": "0.30.0",
     "commonmark-react-renderer": "4.3.5",
     "deep-equal": "2.0.5",
@@ -101,6 +102,7 @@
     "@storybook/react-native": "5.3.25",
     "@storybook/react-native-server": "5.3.23",
     "@testing-library/react-native": "7.2.0",
+    "@types/base-64": "1.0.0",
     "@types/enzyme": "3.10.9",
     "@types/enzyme-adapter-react-16": "1.0.6",
     "@types/jest": "26.0.24",