Support registering graphs

[guyca]

This PR adds a new API that will allow decoupling injection targets from graphs.

API

Registering a graph

Registering a graph will let you use it by its registered key.

Obsidian.registerGraph('FooGraph', () => require('some/path/FooGraph).default);

injectHook

Inject your target with the key used to register the graph.

export const useFoo = injectHook(useFooHook, 'FooGraph');

Obsidian.obtain

Registered graphs can still be used as service locators.

import type FooGraph from 'some/path/FooGraph';

Obsidian.obtain<FooGraph>('FooGraph').foo();

Tasks

• obtain registered graphs
• inject hooks
• inject components
• late inject
• @Injectable(key)
• registered subgraphs [ON HOLD: breaks the unresolved dependencies ESLint rule]
• documentation