Removing BrokerApi from namespace

[mvehar]

Remove \BrokeApi from PHP namespaces

Description

Removed \BrokeApi from PHP namespaces, now only defined namespace in generator parameters is used

Motivation and context

When generating PHP files for external project the generated files were not PSR-4 compliant, since added BrokerApi string in namespace required additional sub-folder

How has this been tested?

composer run test and with external project

Screenshots (if appropriate)

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• 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:

• 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.
• If my change requires a change to the documentation, I have updated it accordingly.