feat: add shims for file system providers

shims/providers/default.js

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+const { Default } = require('../../src/providers/index');
+module.exports = Default;

shims/providers/indexeddb.js

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+const IndexedDB = require('../../src/providers/indexeddb');
+module.exports = IndexedDB;

shims/providers/memory.js

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+const Memory = require('../../src/providers/memory');
+module.exports = Memory;