Switch default admin theme to the Gin Admin theme as Vartheme Claro is deprecated

Problem/Motivation

Requested by Razem

Paraphrased

• Deprecate Vartheme Claro from being the default Admin theme in Varbase
• Require the Gin Admin theme and use it directly ( not a sub theme of it )
• Setup default configs and custom RTL font styling to libraries in Varbase Admin, custom fixes ( better to have custom fixes as a Patch/MR for the Gin theme directly with more support for fixes and integrations with the Gin Admin them directly)
• Move the style of Varbase Installer to Varbase profile.
• Change the default admin theme to Gin
• Use Drupal Recipes and default config to change needed configs

Proposed resolution

#3426304: Deprecate Vartheme Claro theme in fever of using the Gin Admin theme directly in Varbase
#3426299: Add the Gin Admin theme to Varbase Core and deprecate Vartheme Claro theme

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 and Update Helper on new feature change/addition
• ✅ Release varbase-10.0.0-rc2

Varbase update type

• ✅ No Update
• ➖ Optional Update
• ➖ Forced Update
• ➖ Forced Update if Unchanged

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Issue #3426873: Switched default admin theme to the Gin Admin theme as Vartheme Claro is deprecated