Fix default updaters bug in GeographicPartition

[InnovativeInventor]

Several GerryChain users have been reporting a bug in the most recent version of GerryChain where the default updaters in a GeographicPartition (e.g. area, boundary_nodes, etc.) are not being instantiated properly. This PR fixes the bug and adds regression tests to ensure that this doesn't happen again.

It also renames the use_cut_edges flag to use_default_updaters, which more accurately reflects its intended purpose.

[codecov-commenter]

Codecov Report

Merging #391 (2638415) into main (005d77a) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #391   +/-   ##
=======================================
  Coverage   87.83%   87.84%           
=======================================
  Files          37       37           
  Lines        1735     1736    +1     
=======================================
+ Hits         1524     1525    +1     
  Misses        211      211           

Impacted Files	Coverage Δ
gerrychain/partition/partition.py	92.30% <100.00%> (+0.08%)	⬆️

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[gabeschoenbach]

Looks good!