test: unit tests for swapexists

[aorumbayev]

Description

Please explain the changes you made here

more unit tests

Checklist

Please, make sure to comply with the checklist below before expecting review

• Code compiles correctly
• Created tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary

[codecov]

Codecov Report

Merging #145 (0227bf4) into main (501b71d) will increase coverage by 3.64%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #145      +/-   ##
==========================================
+ Coverage   45.98%   49.63%   +3.64%     
==========================================
  Files          84       84              
  Lines        1957     1910      -47     
  Branches      184      175       -9     
==========================================
+ Hits          900      948      +48     
+ Misses       1039      945      -94     
+ Partials       18       17       -1     

Impacted Files	Coverage Δ
src/components/Headers/NavBar.tsx	57.77% <ø> (+0.74%)	⬆️
src/redux/helpers/utilities.ts	64.28% <100.00%> (+61.00%)	⬆️
src/utils/api/transactions/submitTransactions.ts	100.00% <0.00%> (+81.81%)	⬆️
src/components/Layouts/Layout.tsx	89.47% <0.00%> (+89.47%)	⬆️
src/utils/api/transactions/waitForTransaction.ts	100.00% <0.00%> (+92.30%)	⬆️
src/utils/api/swaps/swapExists.ts	100.00% <0.00%> (+100.00%)	⬆️

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