[FEAT] Support configuration updates

[brooksmtownsend]

See wasmCloud/wasmCloud#1648 for the original issue for implementing this in the wasmCloud host, and wasmCloud/wasmCloud#2436 for the implementation in the host and provider-sdk on the Rust side.

The Go provider SDK should add an additional subject to listen on, wasmbus.ctl.<lattice>.<provider_id>.config.update where capability providers can receive a map[string]string that updates their internal configuration. This should be another option when initializing the provider so that if config changes, like a default port or default connection string, capability provider developers can take the steps needed to update the provider.

This is a good-first-issue since there's a reference implementation in Rust, and is just additive 😄 It would be a good practice to add a piece of configuration to the example, like a prefix for the sync.Map, and then update it for testing. This feature should be available for testing in wasmCloud 1.2, so you may need to run wasmCloud from main or from a release candidate until it's ready.