Add basic Macos signing + notarizing workflow (#2319)

Adds basic CircleCI workflow to sign, notarize,
and staple MacOS app bundle and associated DMG,
then publishes signed binary in CircleCI artifacts

Signed-off-by: Adam Treat <treat.adam@gmail.com>

.circleci/grab_notary_id.py

@@ -0,0 +1,17 @@
+import re
+import sys
+
+ID_REG = r"id: (.*)"
+
+def main() -> None:
+    notary_log = sys.argv[1]
+    with open(notary_log, "r") as f:
+        notary_output = f.read()
+        id_m = re.search(ID_REG, notary_output)
+        if id_m:
+            print(id_m.group(1))
+        else:
+            raise RuntimeError("Unable to parse ID from notarization logs")
+
+if __name__ == "__main__":
+    main()