Update packages registries menu as sentence case

What does this MR do and why?

• Updates the Packages & Registries text in sidebar menus as sentence case and replace & with and (Packages and registries) as per the punctuation guidelines.
• Updates the text Packages & Registries in breadcrumbs and title as sentence case and replace & with and Package and registry settings as per the punctuation guidelines.
• Replaces the respective documentation and test references with the above updates.

Screenshots or screen recordings

Project sidebar:

Project settings:

Group sidebar:

Group settings:

Group Settings breadcrumb & title:

Project Settings breadcrumb & title:

How to set up and validate locally

1. Check the Packages and registries sidebar menu from both Group and project.
2. Check the Packages and registries under settings menu from both Group and project.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #370775 (closed)