Add WithPerTenantOptions overload that exposes IServiceProvider

My team has ran into several cases where having access to IServiceProvider in the context of resolving options is necessary. We have achieved this by reimplementing WithPerTenantNamedOptions, but having an out-of-the box override with the following signature would be preferred:

public FinbuckleMultiTenantBuilder<TTenantInfo> WithPerTenantNamedOptions<TOptions>(string? name,
    Action<IServiceProvider, TOptions, TTenantInfo> tenantConfigureNamedOptions) where TOptions : class, new()

[AndrewTriesToCode]

I probably can I the next two weeks – day job requires me to travel next week so either I will get no Finbuckle coding time or plenty of time–hard to say. If you have time I’d welcome a PR on that or otherwise use your own extension method for the time being.

[goldsam]

Thanks for accepting my changes! I look forward to the next release featuring these changes 😀