execute compiler rpc in a task

[mhanberg]

this will not block the runtime genserver, so that stdout packets from the port can be forwarded to the LSP process and logged correctly.

it currently synchronously compiles, and then logs the pile of log messages.

when it fires off a task (should be a supervised task), it should set some state to lock the server so that other processes can't ask it for data assuming the code is compiled

or a flag to say its compiling, and only allow rpc's that don't care about that