Refresh GitHub Actions and Appveyor CI

Moved baseline to C++11 due to our dependencies.

- Remove C++98 and C++03 from CI and mark C++11 baseline
- Remove duplicate jobs between Appveyor and GHA
- Disable CMake GHA jobs for now; broken

meta/libraries.json

@@ -13,5 +13,5 @@
     "maintainers": [
         "Jeremy Siek <jeremy.siek -at- gmail.com>"
     ],
-    "cxxstd": "03"
+    "cxxstd": "11"
 }