lv_manip: enhance for_each_sub_lv

lv_manip: enhance for_each_sub_lv

Fix missing 'externalLV' traversing for thins with external origins.

Replace extra for_each_sub_lv_except_pools() with better
internal logic allowing selectively to cut of processed subLV tree.

Extend error code for function 'fn()' when it returns -1 it will
stop futher tree scan for given LV.

Also a bit simplify code to have only one place that
is calling 'fn()' and use level counter to know
depth of traversing.

Update renaming travering to skip trees for pools
and external origins.