SumK generated output in new group 'lda_output', cleaning up.

* updated update_archive.py script to move output elements out
* added clear_lda_output.py script to restore state of converter generated h5
Replaced "== None" with "is None" and similarly for "is not" in U_matrix
operators.operators2 --> operators
Fix to update_archive script
Fix in reading in sumk_lda
Added dmft_output to clear_lda_output.py
Updated example script
Replaced "== None" with "is None" for other py files
Tidying up
Move repeated converter functions in converter_tools.py
Shortened calc_density_correction, more tidying up
Variable name changes for clarity and consistency
Rename gf_struct_corr to gf_struct_sumk
Introduce new maps sumk_to_solver and solver_to_sumk

They take (block,inner)_sumk -> (block,inner)_solver,
and encode all the information contained in map, map_inv,
and map_ind. These functions will be cleaned up soon.
Use solver_to_sumk and solver_to_sumk_block instead of previous maps
Remove all instances of map, map_inv, map_ind
Tidy up of unused functions in sumk_lda
Tidy up of trans_basis
Tidy up of symmetry

*changed map -> orb_map in symmetry to avoid using python keyword
Write shell equivalency information directly into h5 at conversion

* changed shellmap and invshellmap to corr_to_inequiv and inequiv_to_corr
* update_archive now calculates and stores these quantities for old archives