Modify chainiksolverpos_nr error processing logic to use solver interface
tests: Add unit test for singular values using psuedo inverse solver
Modify chainiksolvervel_pinv error processing logic to use solver interface

Provides access to the underlying SVD error code if the SVD computation fails.
vel_pinv: Provide access to number of near zero sigma values.
tests: Update return codes for singular value test
tests:Add fully singular case to singular value test
Merge branch 'fix-pinv-solver-error-logic' of https://github.com/snrkiwi/orocos-kdl into fix-pinv-solver-error-logic