Rename 'node' to 'container' and shorten URLs.

[danielballan]

Closes #472.

To be determined: Should we update the client module and class tiled.client.node.Node to tiled.client.container.Container? I lean "yes" but I do not feel 100% sure. It is technically still a Node, but it is specifically a Container node, so it should be updated, right?

[danielballan]

This also seemed like the right time to rename the queries on specs and structure families to SpecQuery and StructureFamilyQuery, to avoid confusion with the Spec dataclass and the StructureFamily enum. They are in different modules, of course, so they don't technically collide but this seemed likely to be a source of confusion for users.

[padraic-shafer]

To be determined: Should we update the client module and class tiled.client.node.Node to tiled.client.container.Container?

Is there an existing or likely usage where you could meaningfully replace def do_something_with(node: Node): … with e.g. def do_something_with(node: DataFrame): … or def do_something_with(node: Array): …?

If not, then you can comfortably replace …Node with …Container.

[danielballan]

Good point. There are things one can do on a Container that one cannot do on just any generic Node. We should rename so that the typing makes sense. 👍

[padraic-shafer]

I suppose a nice way to transition the node module and its classes would be to create aliases (Node = Container) and a module-level deprecation warning.

[danielballan]

Done!

To make this change fully backward-compatible would get messy very quickly. At this early stage, I think it's better to avoid loading up the codebase with that mess. I am opting to make only a basic effort here---raising clear error message / warnings at least.

There is a corresponding update in Databroker, ready to go once Tiled is released.