feat: add support for host logging, deprecating old topics_logger in favor of host-managed topics logger. updates examples.

[tylerburdsall]

Adds .wit bindings for our host-supported log destinations. Deprecates old topic_logger in favor of the new one. Will be merged when host support is merged.

This also adds support for shipping logs to a desired CloudWatch Logs Group as well as splitting out specific log levels per destination. For example, you can set all logs DEBUG and higher to a topic, but only INFO and higher to a CW Logs Group.

Testing

Verified this works in development cell. Logging example correctly sent logs to my topic, including system logs (when specified).

$ momento topic subscribe --cache my-functions-cache logging-example
INFO [system] "2025-10-09T23:35:11.405715618Z" - web function started
INFO 2025-10-09T23:35:11.407336804Z logging momento-functions/examples/logging.rs:27 Received request: Request { name: "Tyler" }
INFO [system] "2025-10-09T23:35:11.407494289Z" - web function ended

Breaking changes

• momento_functions_log::configure_logging now receives a Vec<ConfigureLoggingInput> so multiple destinations can be configured at once
• momento_functions_log::configure_logging now returns a Result<(), LogConfigError> instead of SetLoggerError
• TopicLogger is no longer supported; deprecated in favor of LogDestination::Topic

[PDXKimani]

I wonder about this length restriction for the host-logging approach. Is it still appropriate?

[kvcache]

This isn't a restriction, it's an initial capacity to help avoid excessive reallocation. That said, we could reach for unsafe here too and reuse the buffer given the single-thread nature of Functions... Let's leave that for another time though :-)

[kvcache]

mostly just have configuration quality of life feedback, which I think is pretty important ffor logging configuration!

[kvcache]

This isn't a restriction, it's an initial capacity to help avoid excessive reallocation. That said, we could reach for unsafe here too and reuse the buffer given the single-thread nature of Functions... Let's leave that for another time though :-)