Add transaction decline reason 'Authentication rejected by cardholder'

[BreD1810]

Before this change, I was getting the following on a transaction:

Error: Serde(Error("unknown variant `AUTHENTICATION_REJECTED_BY_CARDHOLDER`, expected one of `INSUFFICIENT_FUNDS`, `CARD_INACTIVE`, `CARD_BLOCKED`, `INVALID_CVC`, `SCA_NOT_AUTHENTICATED_CARD_NOT_PRESENT`, `STRONG_CUSTOMER_AUTHENTICATION_REQUIRED`, `OTHER`", line: 1, column: 28437))

[codecov]

Codecov Report

Merging #51 (d2b14a2) into main (018d8ef) will increase coverage by 0.36%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #51      +/-   ##
==========================================
+ Coverage   45.86%   46.22%   +0.36%     
==========================================
  Files          19       19              
  Lines         894      900       +6     
==========================================
+ Hits          410      416       +6     
  Misses        484      484              

Impacted Files	Coverage Δ
src/endpoints/transactions.rs	99.46% <100.00%> (+<0.01%)	⬆️

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[danieleades]

thanks for this. changes look good.

I've been toying with the idea of adding a 'catch-all' enum variant for any unrecognised case, to prevent panicking. The tricky thing there is that there's already an Other case (which the API defines), so that might be slightly confusing.