Ability to fetch db names for documents/aggregates from marten options.

[elexisvenator]

Closes #3125

As per the above issue, the usage is as follows:

IQuerySession session;

var schema = session.DocumentStore.Options.Schema;

var a = schema.DatabaseSchemaName;  // "public"
var b = schema.EventsSchemaName;    // "public" // can be different

var c = schema.For<User>();            // "public.mt_doc_user"
var d = schema.For<UserProjection>();  // "public.mt_doc_userprojection"
var e = schema.ForStreams();           // "public.mt_streams"
var f = schema.ForEvents();            // "public.mt_events"
var g = schema.ForEventProgression();  // "public.mt_event_progression"

var h = schema.For<User>(qualified: false);            // "mt_doc_user"
var i = schema.For<UserProjection>(qualified: false);  // "mt_doc_userprojection"
var j = schema.ForStreams(qualified: false);           // "mt_streams"
var k = schema.ForEvents(qualified: false);            // "mt_events"
var l = schema.ForEventProgression(qualified: false);  // "mt_event_progression"

I have updated the advanced sql examples to fetch table names this way, and have added a section to the documentation describing the functionality.

[Hawxy]

Could we add an overload that accepts Type as a parameter? I could see a scenario where someone wants to loop through an array of types to run sql against multiple tables.

[jeremydmiller]

I'll do that in a bit. It's almost inevitable that using Method means you'll eventually want Method(Type)