Add network logging support

[stevensJourney]

Overview

This adds the ability to log PowerSync network requests. This is the Swift port of powersync-ja/powersync-kotlin#229.

This also removes the experimental ConnectionMethod options which have recently been removed from the Kotlin SDK.

[simolus3]

Is there a reason we're not re-using LoggerProtocol for this? Could the SyncRequestLoggerConfiguration take a LoggerProtocol, a severity (probably defaulting to something verbose) and the log level and then post messages there?

[stevensJourney]

I initially considered reusing LoggerProtocol, but opted for the current SyncRequestLogger.

The PowerSync network logger is focused specifically on HTTP request/response data, and uses a custom "log-level" SyncRequestLogLevel which controls what type of network data is emitted (headers, body, etc.), rather than traditional severity levels like .debug, .info, etc.

If we used LoggerProtocol, users would have to provide: a logger instance, a SyncRequestLogLevel and a corresponding LoggerLevel to use for all network messages. That felt slightly more complex and potentially confusing. With SyncRequestLogger, we give devs full control to decide how to map messages to their own logging system or levels inside log(_:).

There might not be a strong use case for this, but SyncRequestLogger also makes it slightly easier to process network logs without the use of a traditional logger.

[simolus3]

Fair. I wonder if there should be another constructor on SyncRequestLoggerConfiguration that takes the logger, SyncRequestLogLevel and LoggerLevel. That way users who already have a logger don't need to implement another interface, and those who want them separate can use SyncRequestLogger?

[stevensJourney]

👍 I like that idea. I've implemented your suggestion of an additional constructor. I've also removed SyncRequestLogger for a single closure based approach.