Add optional-chaining and nullish-coalescing to preset-env (#10811)

* Add support for optional-chaining (stage 4) in present-env

* revert babel-preset-env built-in-modules.json

* add shipped proposal syntax map entry, optional chaining

* update remaining syntax plugin references, proposal description

* Add support for nullish coalescing operator in preset-env

* selectively enable sort-keys rule

* enforce sort-keys on shipped-proposals

* don't use Object.entries()

* Update fixtures

packages/babel-compat-data/data/native-modules.json

@@ -6,7 +6,7 @@
     "safari": "10.1",
     "opera": "48",
     "ios_saf": "10.3",
-    "and_chr": "71",
-    "and_ff": "64"
+    "and_chr": "74",
+    "and_ff": "66"
   }
 }