[CPP] Fix possessive messages for players

[ampitere]

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• I understand I should leave resolving conversations to the LandSandBoat team so that reviewers won't miss what was said.
• I have read and understood the Contributing Guide and the Code of Conduct.
• 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?

Fixes an issue where messages relating to the player were not possessive. Resolves #5600.

Steps to test these changes

1. Give yourself paralyze (!exec target:addStatusEffect(xi.effect.PARALYSIS, 100, 0, 90))
2. Attack a mob
3. Alternatively use an ability on yourself or ready a weaponskill or let an effect fall off