fix: GET /transactions: pagination with token always returns a "previous" when moving backward, even on the first page

[antoinegelloz]

GET /transactions: pagination with token always returns a "previous" when moving backward, even on the first page.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring / Technical debt

What parts of the code are impacted ?

GET /transactions

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• 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

[codecov]

Codecov Report

Merging #266 (b3ad5a1) into feature/num-567-let-users-get-more-than-15-transactions (d6c66c7) will increase coverage by 0.08%.
The diff coverage is 100.00%.

@@                                     Coverage Diff                                     @@
##           feature/num-567-let-users-get-more-than-15-transactions     #266      +/-   ##
===========================================================================================
+ Coverage                                                    71.10%   71.19%   +0.08%     
===========================================================================================
  Files                                                           76       76              
  Lines                                                         3970     3968       -2     
===========================================================================================
+ Hits                                                          2823     2825       +2     
+ Misses                                                         901      898       -3     
+ Partials                                                       246      245       -1     

Impacted Files	Coverage Δ
pkg/storage/sqlstorage/transactions.go	85.14% <100.00%> (-0.17%)	⬇️
pkg/analytics/segment.go	90.62% <0.00%> (+6.25%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d6c66c7...b3ad5a1. Read the comment docs.