Fix filter chain configuration parameter loading

[paucarrecardona]

Trying to use filters_demo_launch.py which has the following (filters)[https://github.com/ANYbotics/grid_map/blob/ros2/grid_map_demos/config/filters_demo_filter_chain.yaml] it fails to load with a runtime error.

The PR allows loading of the configuration. It has also been tested with other configuration parameters successfully.

[jonbinney]

Could you look through CI and address the failing tests? It looks like cpplint is failing, at least on humble.

[paucarrecardona]

@jonbinney basically there is no longer "parameter redeclaration" and no default values. It creates new parameters with every new filter.
Without the changes it crashes with

terminate called after throwing an instance of 'rclcpp::exceptions::InvalidParameterTypeException'
   what():  parameter 'filters.filter1.name' has invalid type: cannot undeclare an statically typed parameter

[meyerj]

type_desc and name_desc are declared and populated, but then unused besides the name. I suggest to use the declare_parameter() overloads that accept a rcl_interfaces::msg::ParameterDescriptor, same as before.

[meyerj]

Or directly pass the name only without the extra descriptor declarations, if the default descriptors will do.