Blocks POC (Rhino, Acad)

[didimitrie]

Unfortunately does more things that originally intended 😅

What/why? Adds support for sending blocks (non-dynamic!) between rhino<>rhino, acad<>acad, and rhino<>acad. It's also driving this in a new, "cleaner" approach that was discussed... since pretty much the retreat in Athens 😅

Tl;dr:

• Adds IInstanceObjectManager interface
• Implements InstanceObjectManager in Rhino
• Implements InstanceObjectManager in Acad

The above provide support for sending and receiving blocks (static blocks, not dynamic blocks) to and from Rhino and Acad.

Extras:

• Have to deal with conversion of Matrix4x4 to native app in the InstanceObjectManager, this means that there's some scaling code in there. The good news is there's no dependency on the old Transform class.
• Had to add a RhinoLayerManager class to simplify conversions

A question that arises fast but i do not want to solve in this PR: formalisation of the root commit object structure: yes, it's a collection, but where do we store definition proxy objects? currently attaching as a dynamic prop, so we're relying on convention. Imho, good enough to merge for now as I'd want to implement one extra similar case before we generalise (eg., rhino groups? materials?)

more notes: https://www.notion.so/speckle/Blocks-Journal-e358f6a4db7c46859ae419ff2c7dbdd6 jira tix: https://spockle.atlassian.net/browse/DUI3-120

[BovineOx]

I did just ask for a ticket to make it interfaced out and add some tests and a question about splitting the interface but that's all

[adamhathcock]

Needs https://github.com/specklesystems/speckle-sharp-sdk/pull/6