[template/angular-sxp] Fix build error of angular-sxp, service not found

[yavorsk]

• [ ] This PR follows the Contribution Guide
• [x] Changelog updated
• [ ] Upgrade guide entry added

Description / Motivation

Fixes a build error of angular+angular-sxp app by removing the angular-xmcloud specific link service from app.module and providing it via provideIn='root'

Testing Details

• [ ] Unit Test Added
• [ ] Manual Test/Other (Please elaborate)

Types of changes

• [x] 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 change)