MMOexp: Higher level invaders can opt in/out of this feature

Invasion Rune Level Matchmaking

- For each password summon that is outside and higher than the host's rune level
matchmaking range, an invasion slot will expand its level tolerance to Elden Ring Runes include
higher level invaders to match the password summon which will be prioritized.

- Higher level invaders can opt in/out of this feature via a toggle in the
Multiplayer settings called "Downscale Invasions"

- When higher level invaders invade a lower level world with password summons, they
will have the same downscaling as the password summons.

- Higher level invasion slots will persist until the host rests at a site of grace
or dies.

Example:

Player 1 is RL 150. Normally, they can only be invaded by players with RL ranged
from 119-166. If they summon a player that is RL 200, an open invader slot or the
next one to be cleared will have an RL range of 119 - 222. If during this time, an
RL 150 and and RL 222 are searching for elden ring items buy online invasions, the RL 222 will have priority.