Add implementations for new rmw functions

[christophebedard]

Similar to #343. This adds implementations for some new rmw functions:

1. Content-filtered topics: Add support for content filtered topics ros2/rmw#302
   1. rmw_subscription_set_content_filter()
   2. rmw_subscription_get_content_filter()
2. Event types: Added rmw_event_type_is_supported ros2/rmw#395
   1. rmw_event_type_is_supported()
3. Client GID: Add rmw_get_gid_for_client method ros2/rmw#327
   1. rmw_get_gid_for_client()
4. Client & service actual QoS: Add client/service QoS getters ros2/rmw#314
   1. rmw_client_request_publisher_get_actual_qos()
   2. rmw_client_response_subscription_get_actual_qos()
   3. rmw_service_request_subscription_get_actual_qos()
   4. rmw_service_response_publisher_get_actual_qos()
5. Event callbacks: Add EventsExecutor ros2/rmw#286
   1. rmw_subscription_set_on_new_message_callback()
   2. rmw_service_set_on_new_request_callback()
   3. rmw_client_set_on_new_response_callback()
   4. rmw_event_set_callback()
6. Feature support: Add sequence numbers to message info structure ros2/rmw#318
   1. rmw_feature_supported()

[codecov]

Codecov Report

❌ Patch coverage is 0% with 66 lines in your changes missing coverage. Please review.
✅ Project coverage is 50.96%. Comparing base (8c51b2c) to head (f5a5759).
⚠️ Report is 1 commits behind head on rolling.

Files with missing lines	Patch %	Lines
rmw_email_cpp/src/rmw_subscription.cpp	0.00%	14 Missing ⚠️
rmw_email_cpp/src/rmw_client.cpp	0.00%	13 Missing ⚠️
rmw_email_cpp/src/rmw_service.cpp	0.00%	13 Missing ⚠️
rmw_email_cpp/src/rmw_features.cpp	0.00%	12 Missing ⚠️
rmw_email_cpp/src/rmw_gid.cpp	0.00%	9 Missing ⚠️
rmw_email_cpp/src/rmw_event.cpp	0.00%	5 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           rolling     #344      +/-   ##
===========================================
- Coverage    52.14%   50.96%   -1.19%     
===========================================
  Files           87       88       +1     
  Lines         2838     2904      +66     
  Branches       846      846              
===========================================
  Hits          1480     1480              
- Misses        1261     1327      +66     
  Partials        97       97              

Flag	Coverage Δ
email	50.96% <0.00%> (-1.19%)	⬇️
rmw-email-cpp	50.96% <0.00%> (-1.19%)	⬇️

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