refactor!(NODE-3295): Support node 12+ and reconfigure CI (#2864)

- Supported Node engine is now 12+
- No longer testing Node 10 in CI
- Simplified CI platform matrix: win64-vs2019/ubuntu-18.04/macos-10.14
- Run FLE/OCSP/TLS tests on all platforms
- Add server version 5.0 to the matrix (resolves NODE-3306)

Author: nbbeeken

.eslintrc.json

@@ -2,7 +2,7 @@
   "root": true,
   "parser": "@typescript-eslint/parser",
   "parserOptions": {
-    "ecmaVersion": 2018
+    "ecmaVersion": 2019
   },
   "plugins": [
     "@typescript-eslint",