NFC: Plantain parser Last payment amount fix

[mxcdoam]

What's new

• The current parser shows the correct result for "last payment amount" only if the top up amount was 3 digits long, if it is longer - the parser shows incorrect value instead of the real amount. This should fix this issue for top ups highter than 999 RUB.

Verification

• Compile plantain_parser.fal with ./fbt fap_dist, then put it in /apps_data/nfc/plugins. Run the NFC app and read a plantain card which was topped up for >=1000 RUB.

Checklist (For Reviewer)

• PR has description of feature/bug or link to Confluence/Jira task
• Description contains actions to verify feature/bugfix
• I've built this code, uploaded it to the device and verified feature/bugfix