chore(tsconfig): enable noImplicitOverride, disallow unreachable code & unused labels

Tighten the shared tsconfig baseline with three additional strict flags: noImplicitOverride, allowUnreachableCode:false, allowUnusedLabels:false.

Author: veillette

tsconfig.json

@@ -16,6 +16,9 @@
     "noUnusedLocals": true,
     "noUnusedParameters": true,
     "noFallthroughCasesInSwitch": true,
+    "noImplicitOverride": true,
+    "allowUnreachableCode": false,
+    "allowUnusedLabels": false,
     "forceConsistentCasingInFileNames": true,
     "isolatedModules": true,
     "verbatimModuleSyntax": true,