Fix Reference keyword export: use correct keyword variable and case-insensitive match

[eodorfman111]

This pull request addresses the bug described in Wildbook issue #1210 (Reference keywords not appearing in the annotation export).

Changes

• The EncounterAnnotationExportExcelFile now writes the correct Keyword object to the "Reference" column instead of using the previous LabelledKeyword, ensuring that reference keywords populate in the export.
• The check for the "Reference" keyword is now case-insensitive (equalsIgnoreCase) so that different capitalizations are handled.
• The export loop now breaks as soon as the reference keyword is found to avoid redundant processing.

Issue link

Fixes Wildbook/Wildbook#1210

Please let me know if any additional changes or tests are needed.

[naknomum]

thanks for your work on this @eodorfman111 . i have looked at the existing code and what it was doing and talked with the team. it seems the previous code was focused on only Keywords that had a name of Reference. this seems to have been a choice that no longer is relevant.

so what we need instead is for the export to populate the column with all Keywords. this should be more similar to the way LabeledKeywords is done in the block before Keywords -- basically no check on value, just add every keyword to the column. for reference on what is needed, you can check out this community post.

please let me know if you have any questions. feel free to start another PR if you wish to take on this issue with these changes.

[goddesswarship]

@eodorfman111 Checking in to see if you need any help with the review @naknomum provided on your PR