fix(cli): parse IR json with streaming parser

[mstade]

PR #4640 fixed the issue reported in #4639, but sadly this was only part of the solution as the IR JSON is also read and parsed by the generators, causing similar issues as those reported in #4639.

For more context, see: https://github.com/fern-api/fern/pull/4640#issuecomment-2350992867.

This PR introduces a new function streamObjectFromFile to the fs-utils package. The function reads a JSON file and returns a Promise that resolves to the parsed JSON object.

Changes

• Added a new function streamObjectFromFile to the fs-utils package.
• The function reads a JSON file and returns a Promise that resolves to the parsed JSON object.
• The function uses the createReadStream function from the fs module to create a read stream for the file.
• The StreamObject class from the stream-json module is used to parse the JSON data.
• The stream-json package is added to the dependencies of the fs-utils package.
• The @types/stream-json package is added to the devDependencies of the fs-utils package.
• The stream-json package is added to the dependencies of the cli package.
• The @types/stream-json package is added to the dependencies of the cli package.

[dsinghvi]

@mstade looking into this now!

[dsinghvi]

@mstade closing your PR in favor of https://github.com/fern-api/fern/pull/4647