refactor(coverage): move re-usable parts to base provider (#6665)

Author: AriPerkkio

packages/coverage-istanbul/package.json

@@ -62,6 +62,7 @@
     "@types/istanbul-lib-report": "^3.0.3",
     "@types/istanbul-lib-source-maps": "^4.0.4",
     "@types/istanbul-reports": "^3.0.4",
+    "@types/test-exclude": "^6.0.2",
     "pathe": "^1.1.2",
     "vitest": "workspace:*"
   }