…DI approach for #455

Attempted as much as possible to break few contracts, and provide forwarding to new implementation

Removed dependence on Microsoft.Extensions.Logging, but added Microsoft.Extensions.DependencyInjection

Works by introducing an internal DI ServiceCollection and ServiceProvider available via a singleton resource. This collection can be configured by a consumer, but services will work out the box without any config (just with Null Logging)

Consumers can add own logging, either with AddLogging(), or by telliing xbim to UseLoggerFactory(logFactory).

Removed public Setter ILoggers. Because we're not fully in control of DI composition favoured approach is to inject/pass in ILoggerFactory to key roots. We're using ServiceLocator anti-pattern in other cases as a last resort.

ModelProvider & Factory has been re-worked to actually work with DI.

One subtle change - Previosuly Heuristic ModelProvider kicked in if Esent was loaded. Now that needs to be set explicitly when configuring the app.

i.e. XbimServices.Current.ConfigureServices(s => s.AddXbimToolkit(opt => opt.UseHeuristicModel()));

Legacy 'DI lite' concepts like IfcStore.ModelProviderFactory.UseHeuristicModelProvider() have been remapped to a new approach and Obsoleted.

TODO: many tests use the old obsoleted overloads, which forward onto new .
All tests pass (with one flaky IfcStore ModelProvider test to resolve)

Caused by random sequencing of tests and shared state

Fixed up defaults on obsolete methods so typical upgraders will auto pick up new implementations by default. i.e. will default to ILoggerFactory signature over ILogger when caller didn't provide any logger
Addresses all test warnings except Scanner

…oryModel.

Added some guards/logging to Esent & Heurisrstic ModelProvider infrastructure when used under non WIndows o/s

Replaced by ServiceLocator

None-breaking as these were only added lately after obsoleting the equivalent ILogger param methods and related DI work

We're mix & match xUnit and vsTest... xUnit classes need Bootstrapping reliably or sequencing issues can trigger failures in singleton state

Made redundant by DI