fix: bug when take null

[atsushi421]

Description

takeするデータが無い時に "Copying an ipc_shared_ptr is not allowed if it was created by borrow_loaned_message()." で落ちてしまうバグを修正。具体的には、空の ipc_shared_ptr の時はエラーが出ないようにしました。

Related links

close: #318

How was this PR tested?

• sample application (required)

Notes for reviewers

[github-actions]

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                           GCC Code Coverage Report
Directory: .
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File                                       Lines    Exec  Cover   Missing
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src/agnocastlib/include/agnocast.hpp           2       2   100%   
src/agnocastlib/include/agnocast_executor.hpp
                                               1       0     0%   38
src/agnocastlib/include/agnocast_publisher.hpp
                                              24      19    79%   68-69,78-80
src/agnocastlib/include/agnocast_smart_pointer.hpp
                                              53      50    94%   77,80-81
src/agnocastlib/include/agnocast_topic_info.hpp
                                              13      13   100%   
src/agnocastlib/src/agnocast.cpp              81      15    18%   22,24,27,30,32-34,36,39,42,44-49,53-54,57-61,65-66,70-73,76,79,81-84,87,90,92-93,95-96,101,103-105,108-111,114,116-122,124,137-138,149-150,153-155,160
src/agnocastlib/src/agnocast_component_container.cpp
                                               8       0     0%   5,7,9-10,12-13,15-16
src/agnocastlib/src/agnocast_component_container_mt.cpp
                                              27       0     0%   7,9,11-15,18,20-21,24-25,28-29,32-34,37-39,43-44,46-48,50-51
src/agnocastlib/src/agnocast_executor.cpp
                                              86       0     0%   10,12,14-16,18-20,24,26,29,31-32,35-39,42-45,47-48,51-53,55-58,61-62,67,70,73,75-79,82,86-87,90-91,94,96-100,103,106,110-115,118,121-124,126-129,132,135-137,140,142,145,149-150,153-156,159,162,164-165
src/agnocastlib/src/agnocast_multi_threaded_executor.cpp
                                              49       0     0%   9,13,15-16,18-19,24-25,28-32,35,37-40,43,47,50,52-54,57-59,63,65-66,70,73,76,78-79,81-82,86-87,90,95,99,102-103,106,113-115,118
src/agnocastlib/src/agnocast_publisher.cpp
                                              73       0     0%   5,7,9-15,19-20,27,32,34-39,42-49,54,58-65,68-69,71-74,76-79,81,84-85,89-90,96,100-109,112-113,116,119,121-126,129
src/agnocastlib/src/agnocast_single_threaded_executor.cpp
                                              18       0     0%   10-12,16,18-21,24,28-30,33,35-36,39-41
src/agnocastlib/src/agnocast_smart_pointer.cpp
                                              20       0     0%   5,7-15,19,21-29
src/agnocastlib/src/agnocast_subscription.cpp
                                              87       9    10%   10-12,14,17,21,24-26,28,30,32,34-38,40-44,46,49-56,59-62,64,66,69,72,76-79,81-87,90-91,98,103,105-108,111,114,118-123,125-129,131,133,136,140-141,143-144
src/agnocastlib/src/agnocast_topic_info.cpp
                                              16       0     0%   12,16-17,20-24,28-31,34-37
src/agnocastlib/src/agnocast_utils.cpp        25      23    92%   48,50
------------------------------------------------------------------------------
TOTAL                                        583     131    22%
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