Add linting rule to sort imports

[matthieusieben]

This change allow imports to be cleaned and sorted automatically on file save. It also adds an engine property to NodeJS packages, ensuring proper compatibility for users of our packages.

• Adds eslint-plugin-import recommended rules to eslint config
• Adds import/order rule to force consistent ordering
• Adds eslint-plugin-n to make sure the features we use are consistent with the node version we support (>=18.7.0)
• Adds engines: { node: ">=18.7.0" } to all packages meant for NodeJS

Note

The supported NodeJS version is currently stated to be 18.0.0 but our code relies on features only available since 18.7.0. For this reason, the engines fields was updated to require NodeJS 18.7.0.

Note

This PR adds an engine field to all NodeJS packages to ensure that users of the @atproto packages can be notified by their package manager if their version of NodeJS might cause compatibility issues.