Adds support for sending logs to multiple destinations e.g. to both a in memory log as well as to something else which can be selective about what it logs.

[LukeButters]

Background

[SC-55402]

Makes it possible to add a customer ILogFactory which logs specific events or records metrics while also still logging to the in memory logger.

Here is a very spelled out example of how to use the new classes:

// A thing that creates a new `InMemoryConnectionLog` on each call.
// Create a single one for performance to cache the LogProvider.GetLogger("Halibut")
ICreateNewILog singleInMemoryConntionLogCreator = new InMemoryConnectionLogCreator();

// These log writers only record and can never return logs.
ILogWriter logConnectionErrors = new LogConnectionErrors();
ILogWriter logSecurityEvents = new LogSecurityEvents();

Func<string, ILogWriter[]> logWriterCreator = prefix => new[] {logConnectionErrors, logSecurityEvents};

// Aggregate the logWriters and the in memory connection log creator
ICreateNewILog aggregateLoggerCreator = new AggregateLogWriterLogCreator(singleInMemoryConntionLogCreator, logWriterCreator);

// Now we need it to be a log factory, and for the ILogs to be cached.
ILogFactory logFactory = aggregateLoggerCreator.ToCachingLogFactory();

Changes:

• Adds a new ICreateNewILog which makes new ILogs.
• Adds a InMemoryConnectionLogCreator which just creates new InMemoryConnectionLog
• Adds a ILogWriter which is just like a ILog except that it is write only, you can't read back logs.
• Adds a CachingLogFactory which copies the caching logic from LogFactory. Doing so means it is easy to add new ways of logging since they don't need to concern themselves with caching.
• Removes TestContextLogFactory.cs and replaces it with TestContextLogCreator which is much simpler thanks to splitting out the caching.
• Removes the AggregateILog from tests since we now have this capability from Halibut.
• Adds a AggregateLogWriterLog which sends logs to both a ILog as well as a set of ILogWriter.

How to review this PR

Quality :heavy_check_mark:

Pre-requisites

• [ ] I have read How we use GitHub Issues for help deciding when and where it's appropriate to make an issue.
• [ ] I have considered informing or consulting the right people, according to the ownership map.
• [ ] I have considered appropriate testing for my change.

[shortcut-integration[bot]]

This pull request has been linked to Shortcut Story #55402: Get visibility into polling tentacles connecting to the queue..