fix: remove unnecessary finalize and add copy in First generator

[TStylman]

Removed unnecessary finalize call from Event.evaluate() and added copying of the payload in First.

[github-actions]

Test Results

352 tests  ±0   348 ✅ ±0   57s ⏱️ -18s
 13 suites ±0     4 💤 ±0 
  2 files   ±0     0 ❌ ±0 

Results for commit 17dbeb1. ± Comparison against base commit c61824e.

♻️ This comment has been updated with latest results.

[github-actions]

Package	Line Rate	Branch Rate	Health
metsi.app	83%	70%	✔
metsi.core	86%	68%	✔
metsi.data	76%	43%	➖
metsi.data.conversion	87%	58%	✔
metsi.data.enums	99%	0%	✔
metsi.data.formats	74%	51%	➖
metsi.data.formats.forest_centre	87%	68%	✔
metsi.data.formats.nfi	88%	71%	✔
metsi.data.motti	100%	100%	✔
metsi.data.util	88%	77%	✔
metsi.domain	64%	51%	➖
metsi.domain.forestry_treatments	80%	68%	➖
metsi.domain.natural_processes	68%	50%	➖
metsi.domain.utils	100%	100%	✔
metsi.forestry	51%	21%	❌
metsi.forestry.harvest	91%	69%	✔
metsi.forestry.naturalprocess	32%	29%	❌
metsi.forestry.preprocessing	45%	22%	❌
metsi.forestry.preprocessing.data	100%	100%	✔
metsi.forestry.preprocessing.updating_treatments.fc	42%	0%	❌
metsi.forestry.r.hdmod	100%	100%	✔
Summary	77% (6569 / 8486)	55% (1284 / 2324)	➖

Minimum allowed line rate is 60%