feat: add slice method to array/fixed-endian-factory

[DhruvArvindSingh]

Fixes: #3154

This PR adds 'slice' prototype method in array/fixed-endian-factory.

Updated files(array/fixed-endian-factory):

• README.md
• main.js

Added files(array/fixed-endian-factory):

• benchmark.slice.length.js

• benchmark.slice.js

• test.slice.js

• 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!

[DhruvArvindSingh]

Kindly review this PR, i have added the necessary changes as told in PR #3188

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
array/fixed-endian-factory	$\color{red}1265/1520$ $\color{green}+83.22\%$	$\color{red}176/190$ $\color{green}+92.63\%$	$\color{red}24/34$ $\color{green}+70.59\%$	$\color{red}1265/1520$ $\color{green}+83.22\%$

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

[kgryte]

@DhruvArvindSingh I suggest making whatever changes you made in this PR to your existing PR #3188, instead of opening a new PR.