[Controller Interface] Make assign and release interfaces virtual

[saikishor]

Hello!

I wanted to open this PR to see if making assign_interfaces and release_interfaces is fine or not. This would be helpful if the user wants to deal with a different type instead of having them inside the vectors as it is by default

ros2_control/controller_interface/include/controller_interface/controller_interface_base.hpp

Lines 257 to 259 in ce58fae

	protected:
	std::vector<hardware_interface::LoanedCommandInterface> command_interfaces_;
	std::vector<hardware_interface::LoanedStateInterface> state_interfaces_;

ros2_control/controller_interface/src/controller_interface_base.cpp

Lines 95 to 107 in ce58fae

	void ControllerInterfaceBase::assign_interfaces(
	std::vector<hardware_interface::LoanedCommandInterface> && command_interfaces,
	std::vector<hardware_interface::LoanedStateInterface> && state_interfaces)
	{
	command_interfaces_ = std::forward<decltype(command_interfaces)>(command_interfaces);
	state_interfaces_ = std::forward<decltype(state_interfaces)>(state_interfaces);
	}
	void ControllerInterfaceBase::release_interfaces()
	{
	command_interfaces_.clear();
	state_interfaces_.clear();
	}

By making them virtual, we can let the user able to define the internal structure and then clean them when the release interface is called

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.77%. Comparing base (4472287) to head (a288f57).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1743   +/-   ##
=======================================
  Coverage   86.77%   86.77%           
=======================================
  Files         116      116           
  Lines       10703    10703           
  Branches      981      981           
=======================================
  Hits         9288     9288           
  Misses       1062     1062           
  Partials      353      353           

Flag	Coverage Δ
unittests	86.77% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...controller_interface/controller_interface_base.hpp	87.50% <ø> (ø)

[saikishor]

We need to add @mamueluth to the Reviewers group for the Reviewer Lottery job to succeed!

[bmagyar]

Thanks @saikishor , fixed!

[bmagyar]

Please highlight this and the intended use-case in the docs migration notes

[saikishor]

Please highlight this and the intended use-case in the docs migration notes

@bmagyar Done!. Thank you!

[bmagyar]

thank you!