Investigate having a mandatory long-running stellar core

[Isaiah-Turner]

What

We need to figure out if it is reasonable to require the user to set up and run a stellar-core instance. We need to determine when it is necessary (possibly not needed for ledgers, transactions, and operations).

Why

Captive core takes a while to startup, so we can't run a new instance every time the CLI command is called. We need to have a core instance running in the background that can handle all exports.

[Isaiah-Turner]

We determined that it is reasonable to have this requirement. We are using captive core in order to export accounts, offers, and trades. We have an unbounded export, which will allow us to keep the core instance running.