[MP] RPC visibility-based filtering is missing on server side

[Withaust]

Tested versions

Present in master branch

System information

Does not matter

Issue description

Lets imagine a simple setup in a game where multiple scenes could be used for different levels:

• Client loads into level 1 and gets level 1 to be set as visible for him
• Client loads into level 2, gets level 2 to be set visible for him, while level 1 becomes invisible for him
• Client sends RPC calls to level 1, but since filtering is done on client side, he just ignores it and successfully sends RPC to objects that are supposed to be invisible for him

This is an issue that was there since the visibility introduction, but was never brought up before. Current sender-only visibility filtering is easily circumventable, and additional visibility filtering for RPCs should also be implemented from the server as well.

Steps to reproduce

^^^

Minimal reproduction project (MRP)

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