Handling of multiple lines in BOOT.CSV (or multiple files) is inconsistent

What were you trying to do that didn't work?

fallback.efi shows inconsistent behavior in case multiple entries are present, either with multiple lines in a single BOOT.CSV file or with multiple BOOT.CSV files.

The BootOrder variable has the last entry listed first.
When booting fallback efi picks the first entry though.

Resulting behavior with an empty efi variable store:
First boot: fallback.efi is loaded, creates Boot*, boots first BOOT.CSV line.
Next boots: last BOOT.CSV line is booted directly (via BootOrder + BootNNN).

Please provide the package NVR for which bug is seen:

Found on Fedora 39. Very likely present in all shim versions though.
Also reported in upstream bug tracker (for ubuntu 22.04):
https://github.com/rhboot/shim/issues/554

How reproducible:

100%

Expected results

First boot and subsequent boots should behave the same way.