Pull Out IPFS Gateway Into Separate Binary

[bonedaddy]

At the moment gateway functionality is included within TemporalX's main code base via an opt-in configuration directive, however it provides some unnecessary bloat to the codebase for functionality that is very use-case specific, and probably not something that should be included as a "defacto" feature.

The best option might be to use a separate codebase, which exposes a urfave/cli command that spins up a gateway. This would mean we can include this within the CLI we release, and not have it be part of the main codebase.

This would also mean we can freely add new functionality, a more advanced P2P HTTP proxy, and not have to worry about it impacting the codebase at large.