Change the logo and emblem to the new approved Varbase brand logo for Varbase Project template

Problem/Motivation

The project still ships the old Varbase emblem (the blue square with arrows).
Varbase now has a new approved brand logo: the varbase wordmark
with the blue smile emblem, defined in the approved VB stylesheet and logo
design files.

Proposed resolution

• logo.png, new 512x512 square smile emblem.
• Full wordmark logo SVG/PNG (where the project ships one).
• Emblem color / white / grey variants (where shipped).
• favicon.ico, new emblem favicon (where shipped).
• Navigation sidebar emblem (where the project sets it).

Remaining tasks

• ✅ File an issue about this project
• ✅ Addition/Change/Update/Fix to this project
• ✅ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ✅ Code review from 1 Varbase core team member
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Update Release Notes
• ✅ Release varbase_project-11.0.1, varbase-11.0.0-alpha3, varbase_starter-1.0.0-alpha2

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• chore: #3604079 New approved Varbase brand logo, wordmark, and favicon for Varbase Project