Support "bloopJvmProperties"

[ptwales]

Describe the feature

I would like to limit the amount of memory used by bloop to 4G. I can control the memory used by metals with serverProperties. I see similar controls for ammonite with ammoniteJvmProperties. But I don't see any for bloopJvmProperties.

I would like to be able to do:

metals_config.settings = {
    serverVersion = "latest.stable",
    serverProperties = { "-Xmx4096m" },
    bloopJvmProperties = { "-Xmx4096m" },
}

when plugging in metals.

Potential ways to implement

Looking at the code I think "bloopJvmProperties" just needs to be added to valid_metals_settings in config.lua, and the appropriately documented in metals.txt. And tested, obviously.

I tried just adding the value to my settings table but got hit with a warning message that the option wasn't supported.