Allow transmitting assets over BRP

[janhohenheim]

What problem does this solve or what need does it fill?

Alternative to #19695
Basically, we need a way to let two processes access the same assets for e.g. editors that want to attach to a running game

What solution would you like?

Quoting @mockersf on Discord

do something like brp.server_load("my_path.file") and it returns the bytes that you can load on the brp client side
then you have an asset source that is brp:// and that actually reads the file in the server and sends the bytes to the client

again, not sure if that would work, but:

• client does asset_server.load("brp://my_path.file")
• this gets translated to brp.server_load("my_path.file"), still on the client
• this sends a command to the server to load a file
• server does asset_server.load("my_path.file")
• but not actually a load as we don't want the loaded asset on the server, just for it to setup the reader with the asset bytes
• the server sends the bytes over brp to the client
• client starts the asset loader on this reader

What alternative(s) have you considered?

Other solutions to solve and/or work around the problem presented.

Additional context

Open up the full asset path