Problems with Raid start

Currently there are multiple problems with how Raids are started, when doing so without the "Update 1.21"-Experiment:
1. the Bad Omen effect is no longer removed, see also MC-269963
2. particles are missing, see also MC-270441
3. advancement "Voluntary exile" is not triggered
4. statistic "Raid triggered" is not getting incremented
5. Pillagers and Vindicators - in additional waves - don't spawn with enchanted weapons

Steps to reproduce

• Create a new superflat world
• Go to the next village
• Give yourself the bad omen effect /effect give @s minecraft:bad_omen

Expected behavior

The same as in 1.20.4