Audit renamed components for configuration bugs

[spencergilbert]

While renaming our gcp_stackdriver sinks I noticed we may not be properly handling the backward compatible configuration properly.

https://github.com/vectordotdev/vector/blob/master/src/sources/prometheus/scrape.rs#L173-L176

vs

https://github.com/vectordotdev/vector/blob/master/src/sinks/prometheus/exporter.rs#L157-L163

Related: serde-rs/serde#1504
Related: #12162 (possibly)

As the backward compatibility is only for the component's type we need to ensure the options are maintained across both names until we can deprecate the older names (which we should do more regularly to avoid these bugs and user/programmer footguns).

cc @jszwedko @tobz