Copy using the SDK's copy method

[marivaldojr]

Description

Changes the copy method to use the SDK copy method, which uses the Backblaze API b2_copy_file operation.

Motivation and context

The SDK has a copy method to perform tue copy through the b2_copy_file operation from the Backblaze API.

The current implementation cannot copy a file from one location to another in Backblaze.

How has this been tested?

I have loaded these changes, plus gliterd/laravel-backblaze-b2 into my Laravel project and tested.

Screenshots (if appropriate)

Types of changes

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

Go over all the following points, and put an x in all the boxes that apply.

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• I have read the CONTRIBUTING document.
• My pull request addresses exactly one patch/feature.
• I have created a branch for this patch/feature.
• Each individual commit in the pull request is meaningful.
• I have added tests to cover my changes.
• All new and existing tests passed.
• If my change requires a change to the documentation, I have updated it accordingly.
• My code follows the code style of this project.

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