Added stats/incr/nanmaape package

[vishwajeet1729]

Resolves #5562

Description

This pull request adds an incremental accumulator for computing the mean arctangent absolute percentage error (MAAPE) while ignoring NaNs (incrnanmaape). This function provides an online algorithm that updates the moving mean without being affected by missing (NaN) values.
This pull request:

This pull request:

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

---

@stdlib-js/reviewers

[stdlib-bot]

Hello! Thank you for your contribution to stdlib.

We noticed that the contributing guidelines acknowledgment is missing from your pull request. Here's what you need to do:

1. Please read our contributing guidelines.

2. Update your pull request description to include this checked box:

   - [x] Read, understood, and followed the [contributing guidelines](https://github.com/stdlib-js/stdlib/blob/develop/CONTRIBUTING.md)

This acknowledgment confirms that you've read the guidelines, which include:

• The developer's certificate of origin
• Your agreement to license your contributions under the project's terms

We can't review or accept contributions without this acknowledgment.

Thank you for your understanding and cooperation. We look forward to reviewing your contribution!

[stdlib-bot]

👋 Hi there! 👋

And thank you for opening your first pull request! We will review it shortly. 🏃 💨

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/incr/nanmaape	$\color{green}124/124$ $\color{green}+100.00\%$	$\color{green}9/9$ $\color{green}+100.00\%$	$\color{green}2/2$ $\color{green}+100.00\%$	$\color{green}124/124$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[vishwajeet1729]

@kgryte can you please review this , any changes let me know