Added custom admin logo functionality

[konarshankar07]

Committer: Shankar Konar konar.shankar2013@gmail.com

Description (*)

This PR will add the functionality to add the custom admin logo from the backend configuration

Related Pull Requests

Fixed Issues (if relevant)

1. Fixes mage-os/mageos-magento2#<issue_number>

Manual testing scenarios (*)

1. Login in admin
2. Go to Store -> Configuration -> Advanced -> Admin -> Admin Logo
3. Upload custom logo for the admin page and menu

Expected result:
Custom logo will be visible in the admin menu and admin login page

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• README.md files for modified modules are updated and included in the pull request if any README.md predefined sections require an update
• All automated tests passed successfully (all builds are green)

[rhoerr]

Thanks for the PR! We'll review.

[rhoerr]

Related module, for reference: https://github.com/element119/module-custom-admin-logo

I think we should consider whether we can use that module as-is, or by suggesting changes to them, rather than copying it into our core.

One issue with it is the composer constraint is out of date with current Magento supported versions of PHP. The code looks 8.4 compatible though.