Imu Interface with implementation for Adis16448

[4c3y]

Features

• SPI Driver with custom burst read
• Generic interface for IMUs
• Launch files
• rviz visualization
• Some unittests

[4c3y]

Thanks for the great feedback! I will implement these changes asap.

I'll also add a few more things that I've discussed with @michaelpantic:

• Add Log++ as a submodule
• Replace vec3 with Eigen::vector3d