[rcl_action] Implement goal handle

[jacobperron]

• Goal handle implementation and unit tests.
• Added check to goal state machine transition function for index out-of-bounds

[jacobperron]

CI (up to rcl_action):

• Linux
• Linux-aarch64
• macOS
• Windows

[sloretz]

LGTM, just minor comments

[sloretz]

nit, rcl_action_goal_handle_is_valid() also checks if goal_handle is NULL. This check could be removed.

[jacobperron]

Following the service/client implementations in rcl, I thought we could make the distinction of an invalid argument vs. invalid object (ie, null argument vs uninitialized struct). But I now see that this logic is not consistent in rcl. For example,

client.c makes the distinction:

rcl/rcl/src/rcl/client.c

Lines 198 to 208 in 1120b2f

	rcl_ret_t
	rcl_client_fini(rcl_client_t * client, rcl_node_t * node)
	{
	(void)node;
	RCUTILS_LOG_DEBUG_NAMED(ROS_PACKAGE_NAME, "Finalizing client");
	rcl_ret_t result = RCL_RET_OK;
	RCL_CHECK_ARGUMENT_FOR_NULL(client, RCL_RET_INVALID_ARGUMENT);
	RCL_CHECK_ARGUMENT_FOR_NULL(node, RCL_RET_INVALID_ARGUMENT);
	if (!rcl_node_is_valid(node)) {
	return RCL_RET_NODE_INVALID;
	}

subscription.c does not:

rcl/rcl/src/rcl/subscription.c

Lines 267 to 276 in 1120b2f

	rcl_ret_t
	rcl_take_serialized_message(
	const rcl_subscription_t * subscription,
	rcl_serialized_message_t * serialized_message,
	rmw_message_info_t * message_info)
	{
	RCUTILS_LOG_DEBUG_NAMED(ROS_PACKAGE_NAME, "Subscription taking serialized message");
	if (!rcl_subscription_is_valid(subscription)) {
	return RCL_RET_SUBSCRIPTION_INVALID; // error message already set
	}

[hidmic]

Then it's a good opportunity to make it consistent :)

[jacobperron]

Removed the check (and other similar redundant checks) in 8c65da8
Rather than distinguishing a null pointer vs uninitialized object by return code, we can use the error message instead.

[jacobperron]

Follow-up for rcl #321

[hidmic]

Looks awesome! Left a few comments here and there.

[hidmic]

Then it's a good opportunity to make it consistent :)

[jacobperron]

CI up to rcl_action:

• Linux
• Linux-aarch64
• macOS
• Windows

[hidmic]

LGTM!

[jacobperron]

Fix Clang warning:

• Linux
• Linux-aarch64
• macOS
• Windows