3739 performance improvement

[jadekstewart3]

Checklist:

[x] I have performed a self-review of my own code,
[x] I have commented my code, particularly in hard-to-understand areas,
[x] I have made corresponding changes to the documentation,
[requires production test] I have added tests that prove my fix is effective or that my feature works,

• New and existing unit tests pass locally with my changes ("bundle exec rake"),
  [x] Title include "WIP" if work is in progress.

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Resolves #3727

Description

I have applied the performance enhancement change to other exports that require this change. I also noticed that the uniq method was being called in most of the item_headers methods, I have implemented the use of a Set data structure to eliminate the need for calling uniq, and hopefully improve the over all performance of the exports a bit more.

List any dependencies that are required for this change. (gems, js libraries, etc.)

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

This will require a test on the production copy before merging.

[dorner]

Old:

Donations 127.800472   1.720314 129.520786 (131.679328)
Product Drives 6.785411   0.556920   7.342331 ( 12.114067)
Purchases 0.619706   0.006018   0.625724 (  0.649099)
Requests 0.903873   0.022209   0.926082 (  1.247323)

New:

Donations 1.646709   0.153574   1.800283 (  2.193139)
Product Drives 5.801143   0.713599   6.514742 ( 11.510426)
Purchases 0.152862   0.001546   0.154408 (  0.189587)
Requests 0.760072   0.019760   0.779832 (  0.954667)

Looks like donations was the only one that had a significant performance issue, but this definitely fixes it! Thanks!

[dorner]

Looks good!