Do not repeat `TriggerType` enum in all hardware component classes

[saikishor]

I think it would be a good first issue to not repeat this enum in all classes right?

Originally posted by @bmagyar in #1567 (comment)

[kumar-sanjeeev]

Hi @saikishor, I would like to work on this.

[saikishor]

Hello @kumar-sanjeeev !

Thank you. I've assigned you the issue.

[kumar-sanjeeev]

Thanks. I noticed that TriggerType enum is defined in two files within the include/hardware_interface directory i.e. system_interface.hpp and actuator_interface.hpp.I created a new file hardware_interface_trigger_type.hpp in the same directory to abstract this enum from the hardware component classes and raised the PR. If I missed something, please let me know.