TSV Speed Improvements

[shorowit]

This PR substantially speeds up integrity checks for TSVs with large numbers of rows (and has the side benefit of speeding up sampling) by using caching.

Results for the multifamily project:

Scenario	Before [sec]	After [sec]	Savings
Rake integrity check	1133	110	90%
10k sampling	454	363	20%

I verified that the sampling results are unchanged and that the integrity checks still catch the variety of errors that could be in the TSVs.

@joseph-robertson any chance you could do a quick test run to make sure simulations don't somehow break?

[codecov-io]

Codecov Report

Merging #228 into master will increase coverage by <.01%.
The diff coverage is 79.16%.

@@            Coverage Diff             @@
##           master     #228      +/-   ##
==========================================
+ Coverage   91.18%   91.18%   +<.01%     
==========================================
  Files         166      166              
  Lines       48183    48177       -6     
==========================================
- Hits        43934    43929       -5     
+ Misses       4249     4248       -1

Impacted Files	Coverage Δ
resources/buildstock.rb	65.59% <79.06%> (+0.14%)	⬆️
resources/run_sampling.rb	86.59% <80%> (-0.3%)	⬇️
project_resstock_national/tests/test.rb
project_resstock_testing/tests/test.rb	83.33% <0%> (ø)

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[joseph-robertson]

Testing project seems to run ok.