Simplify cookie logic into a single protection and block 3p cookies (#78)

Improve debugging:
- Fix Mozilla messaging legacy naming: https://app.asana.com/0/1201614831475344/1202339603569805/f
- Fix stack tracing to match against first party and additionally check for http? better: https://app.asana.com/0/892838074342800/1202246422998828/f and
- Error in cookie override TypeError: Failed to construct 'URL': Invalid URL when setting cookie path=/ duckduckgo-privacy-extension#1161
- Cookie messaging: https://app.asana.com/0/0/1202340939105722/f
- Remove duplication of stack processing code

Author: jonathanKingston

.gitattributes

@@ -1 +1,2 @@
 build/** binary
+shared/** binary