Support XML Participant for RPC

[fujitatomoya]

related to eProsima/DDS-Router#489 and ros2/sros2#326

we have PoC code based on the humble version that works as RPC bridge for services and actions via ROS 2 communication. we would like to have feedback and happy to contribute.

[fujitatomoya]

CC: @MiguelCompany

[fujitatomoya]

@Barry-Xu-2018 can you create the draft PR against here from our PoC code?

[Barry-Xu-2018]

can you create the draft PR against here from our PoC code?

Okay. I created a draft PR #141

[Barry-Xu-2018]

I ported #141 to main branch.
The new PR is #166