Refactor FA cookie management and enhance testing

- Updated the FA cookie management in the Scraper::FaHttpClientConfig class to validate cookie formats and handle cookies more robustly.
- Removed the fa.yml configuration file and integrated cookie retrieval directly within the class.
- Added comprehensive tests for cookie handling in the new fa_http_client_config_spec.rb file.
- Updated the Gemfile to include parallel_tests in the test and development group.
- Modified the .rspec file to enable color output for better readability in test results.
- Simplified test commands in the justfile for improved usability.
- Adjusted the rails_helper.rb to ensure the test environment is correctly set up.

justfile

@@ -17,5 +17,5 @@ psql-dump-domain-fa-favs:
     @psql -P pager=off -c 'select user_id, post_id, 1 from domain_fa_favs limit 10000000;' -d redux_prod -h 10.166.33.171 -U scraper_redux -t -A -F ' '
 
 test:
-    RAILS_ENV=test bin/rails test
-    RAILS_ENV=test bin/rake parallel:spec
+    bin/rails test
+    bin/rake parallel:spec