Introduce Design System Page / Design system improvements

Summary:
This diff introduces:

- ScrollContainer
- Make sure Ant Link components always open URLs externally, to avoid users needing to use electron api's
- Introduce a design systems page where people can find docs on how to organise sandy layout, and it also provides a convenient way to test layout mechanisms.
- Fixed several layout bugs found as a result of adding the design system page

In next diff:
- more convenience around organizing paddings
- making the design system accessible from the menu

Reviewed By: cekkaewnumchai

Differential Revision: D23930274

fbshipit-source-id: 4aab058d15b3391287e0e32513a5d83831448857

desktop/yarn.lock

@@ -1199,6 +1199,11 @@
     lodash "^4.17.19"
     to-fast-properties "^2.0.0"
 
+"@base2/pretty-print-object@1.0.0":
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/@base2/pretty-print-object/-/pretty-print-object-1.0.0.tgz#860ce718b0b73f4009e153541faff2cb6b85d047"
+  integrity sha512-4Th98KlMHr5+JkxfcoDT//6vY8vM+iSPrLNpHhRyLx2CFYi8e2RfqPLdpbnpo0Q5lQC5hNB79yes07zb02fvCw==
+
 "@bcoe/v8-coverage@^0.2.3":
   version "0.2.3"
   resolved "https://registry.yarnpkg.com/@bcoe/v8-coverage/-/v8-coverage-0.2.3.tgz#75a2e8b51cb758a7553d6804a5932d7aace75c39"
@@ -7147,6 +7152,13 @@ is-plain-obj@^2.0.0:
   resolved "https://registry.yarnpkg.com/is-plain-obj/-/is-plain-obj-2.1.0.tgz#45e42e37fccf1f40da8e5f76ee21515840c09287"
   integrity sha512-YWnfyRwxL/+SsrWYfOpUtz5b3YD+nyfkHvjbcanzk8zgyO4ASD67uVMRt8k5bM4lLMDnXfriRhOpemw+NfT1eA==
 
+is-plain-object@3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-plain-object/-/is-plain-object-3.0.0.tgz#47bfc5da1b5d50d64110806c199359482e75a928"
+  integrity sha512-tZIpofR+P05k8Aocp7UI/2UTa9lTJSebCXpFFoR9aibpokDj/uXBsJ8luUu0tTVYKkMU6URDUuOfJZ7koewXvg==
+  dependencies:
+    isobject "^4.0.0"
+
 is-plain-object@^2.0.3, is-plain-object@^2.0.4:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/is-plain-object/-/is-plain-object-2.0.4.tgz#2c163b3fafb1b606d9d17928f05c2a1c38e07677"
@@ -7295,6 +7307,11 @@ isobject@^3.0.0, isobject@^3.0.1:
   resolved "https://registry.yarnpkg.com/isobject/-/isobject-3.0.1.tgz#4e431e92b11a9731636aa1f9c8d1ccbcfdab78df"
   integrity sha1-TkMekrEalzFjaqH5yNHMvP2reN8=
 
+isobject@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/isobject/-/isobject-4.0.0.tgz#3f1c9155e73b192022a80819bacd0343711697b0"
+  integrity sha512-S/2fF5wH8SJA/kmwr6HYhK/RI/OkhD84k8ntalo0iJjZikgq1XFvR5M8NPT1x5F7fBwCG3qHfnzeP/Vh/ZxCUA==
+
 isomorphic-fetch@^2.1.1:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/isomorphic-fetch/-/isomorphic-fetch-2.2.1.tgz#611ae1acf14f5e81f729507472819fe9733558a9"
@@ -10617,6 +10634,14 @@ react-dom@^16.13.0:
     prop-types "^15.6.2"
     scheduler "^0.19.1"
 
+react-element-to-jsx-string@^14.3.1:
+  version "14.3.1"
+  resolved "https://registry.yarnpkg.com/react-element-to-jsx-string/-/react-element-to-jsx-string-14.3.1.tgz#a08fa6e46eb76061aca7eabc2e70f433583cb203"
+  integrity sha512-LRdQWRB+xcVPOL4PU4RYuTg6dUJ/FNmaQ8ls6w38YbzkbV6Yr5tFNESroub9GiSghtnMq8dQg2LcNN5aMIDzVg==
+  dependencies:
+    "@base2/pretty-print-object" "1.0.0"
+    is-plain-object "3.0.0"
+
 react-inspector@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/react-inspector/-/react-inspector-3.0.2.tgz#c530a06101f562475537e47df428e1d7aff16ed8"