walletd, grpcd and databased launching not using `runtime.spawning_services`

[zkao]

I also noticed now that the walletd, grpcd and databased launching are not using runtime.spawning_services

Originally posted by @zkao in https://github.com/farcaster-project/farcaster-node/issues/670#issuecomment-1223854206

[zkao]

related to #577

[zkao]

I'd guess we should make a transition from spawning services, into online_services

struct OnlineServices {
syncers: Syncers,
databased: Option<ServiceId>,
// etc...
}

[sedited]

As of #693 we now track online services (including syncers, database, peer, and wallet).