move duplicate element check to before first pass

[MauricioUyaguari]

Summary

• helps with RFC: Address graph building performance and memory usage #927

How did you test this change?

Helps with #927

• Test(s) added
• Manual testing (please provide screenshots/recordings)
• No testing (please provide an explanation)

[changeset-bot]

⚠️ No Changeset found

Latest commit: 013aaa7

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[codecov]

Codecov Report

Merging #968 (013aaa7) into master (6d8ee50) will decrease coverage by 0.00%.
The diff coverage is 91.66%.

@@            Coverage Diff             @@
##           master     #968      +/-   ##
==========================================
- Coverage   42.61%   42.60%   -0.01%     
==========================================
  Files         969      969              
  Lines       44561    44559       -2     
  Branches    10348    10349       +1     
==========================================
- Hits        18989    18986       -3     
- Misses      25498    25499       +1     
  Partials       74       74              

Impacted Files	Coverage Δ
.../to/V1_ProtocolToMetaModelGraphFirstPassBuilder.ts	100.00% <ø> (ø)
packages/legend-graph/src/graph/PureModel.ts	78.80% <75.00%> (-0.08%)	⬇️
...rc/models/protocols/pure/v1/V1_PureGraphManager.ts	56.67% <100.00%> (+0.44%)	⬆️