feat(middleware): add persist api

[AnatoleLucet]

Closes #267, #513

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit dd698f4:

Sandbox	Source
React	Configuration
React Typescript	Configuration
React Browserify	Configuration
React Snowpack	Configuration
React Parcel	Configuration
Next.js	Configuration

[github-actions]

Size Change: +498 B (+5%) 🔍

Total Size: 11.1 kB

Filename	Size	Change
dist/esm/middleware.js	2.78 kB	+288 B (+12%)	⚠️
dist/middleware.js	2.94 kB	+210 B (+8%)	🔍

ℹ️ View Unchanged

Filename	Size
dist/context.js	622 B
dist/esm/context.js	521 B
dist/esm/index.js	1.2 kB
dist/esm/shallow.js	272 B
dist/esm/vanilla.js	520 B
dist/index.js	1.32 kB
dist/shallow.js	318 B
dist/vanilla.js	630 B

_{compressed-size-action}

[dai-shi]

It looks overall good. Some minor things and typing issues need to be addressed.

[AnatoleLucet]

Within the tests, the immer middleware keep the api as StoreApi. Shall I change this middleware using CustomStoreApi?

zustand/tests/middlewareTypes.test.tsx

Line 477 in d063bf0

immer((set, get) => ({

There's still another minor type issue within the middleware with the create function, but I'm unable to find how to solve it. Could you check it out?

[dai-shi]

Shall I change this middleware using CustomStoreApi?

Yeah, I can't think of other ways.
This may require users to update their immer middleware.

There's still another minor type issue within the middleware with the create function, but I'm unable to find how to solve it. Could you check it out?

Hm, I don't know either. Let's add type assertion.

[dai-shi]

The code looks good.