wip(core): Support for 2022 style Design constructor

This is the first commit to tackle some exploratory work
in the context of discussion #2538 that deals with a number
of things, such as:

- Making it easier to attach parts to designs
- Making it easier to attach parts at run-time
- Simplify part inheritance into other designs
- Find ways to handle dependenices across designs
- Find ways to keep the part-specific config with the part

In this initial commit, I've update the Design constructor to
handle two different ways of calling it:

- legacy: new Design(config, plugins, conditionalPlugins)
- 2022: new Design(config)

I didn't want to call this the `new` way because that doesn't
age well, so I went with `legacy` and `2022` and this is how I
will refer to them from now on.

This is very much a work in progress and while I will create a PR
to keep on eye on the tests, I don't expect to merge this as-is.

packages/core/tests/pattern.test.js

@@ -19,6 +19,7 @@ it("Pattern constructor should initialize object", () => {
   expect(pattern.settings.options.percentage).to.equal(0.3);
 });
 
+
 it("Should load percentage options", () => {
   let pattern = new freesewing.Pattern({
     options: {