[lua] Nyzul fixes: NM coffers, Friars Lanterns, removePathos

[wccbuck]

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• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

This PR fixes three issues with Nyzul Island:

1. "Friar's Lantern" mobs in Nyzul did not count towards "Eliminate" objectives because their file was named 'Friar_s_Lantern.lua'. Removed the erroneous underscore in the filename.
2. Vigil weapons / coffers did not drop for about 2/3rds of intended NMs in Nyzul because ID.mob.TAISAIJIN is the first instance of Taisaijin in Nyzul, which is not the end of the NM list.
3. xi.nyzul.removePathos attempted to reference a nil "ID" property instead of "textID".

Steps to test these changes

Ran Nyzul Isle, forced "arcana" floors so I could confirm that Friar's Lantern mobs counted towards Eliminate objectives
Confirmed pathos status effects were cleared on floor change
Confirmed the NM "Maighdean Uaine" dropped a vigil weapon