Use get_activated_edges in undo operation

[kaikue]

Also create empty entries for undos of unsuccessful operations.

[codecov-commenter]

Codecov Report

Merging #315 (a7a0a1c) into akhilesh-unit-tests (f29e70a) will increase coverage by 0.33%.
The diff coverage is 38.77%.

@@                   Coverage Diff                   @@
##           akhilesh-unit-tests     #315      +/-   ##
=======================================================
+ Coverage                37.52%   37.86%   +0.33%     
=======================================================
  Files                       83       83              
  Lines                     7437     8098     +661     
  Branches                  1078     1272     +194     
=======================================================
+ Hits                      2791     3066     +275     
- Misses                    4513     4884     +371     
- Partials                   133      148      +15     

Impacted Files	Coverage Δ
pychunkedgraph/app/segmentation/common.py	0.10% <0.00%> (+0.10%)	⬆️
pychunkedgraph/graph/misc.py	41.44% <ø> (ø)
pychunkedgraph/graph/edges/utils.py	52.30% <10.00%> (-7.70%)	⬇️
pychunkedgraph/graph/operation.py	53.92% <16.66%> (-4.24%)	⬇️
pychunkedgraph/graph/subgraph.py	85.38% <72.72%> (-1.82%)	⬇️
pychunkedgraph/graph/edits.py	96.59% <87.50%> (-0.90%)	⬇️
pychunkedgraph/graph/chunkedgraph.py	76.54% <100.00%> (+0.90%)	⬆️
pychunkedgraph/graph/client/bigtable/client.py	83.91% <0.00%> (+4.48%)	⬆️
... and 1 more

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