feat: migrate /api/users endpoint to /api/v1/users

[jfcalvo]

Description

This PR add a new endpoint GET /api/v1/users returning a list of users if the current user is an owner.

Changes of the new endpoint compared to the old one:

• The returned object is different, in the old endpoint an array with the users is returned. In the new endpoint an object of the type {"items": [...]} is used.
• The returned users as with previous PRs is not including the workspaces attribute and full_name has been removed as well.

Closes #141

Type of change

(Please delete options that are not relevant. Remember to title the PR according to the type of change)

• 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 not work as expected)
• Refactor (change restructuring the codebase without changing functionality)
• Improvement (change adding some improvement to an existing functionality)
• Documentation update

How Has This Been Tested

(Please describe the tests that you ran to verify your changes. And ideally, reference tests)

• Adding new tests.

Checklist

• I added relevant documentation
• follows the style guidelines of this project
• I did a self-review of my code
• I made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I filled out the contributor form (see text above)
• I have added relevant notes to the CHANGELOG.md file (See https://keepachangelog.com/)