fix(ui5-slider/ui5-range-slider): add border to progress indicator

[StefanDimitrov04]

JIIRA: BGSOFUIRILA-4149

[ui5-webcomponents-bot]

🧹 Preview deployment cleaned up: https://pr-12653--ui5-webcomponents.netlify.app

[ndeshev]

The height of the progress track is 4px and the border is 1px with a content-box box-sizing, this makes the total height 6px, while according to the specs it should be 4px for non-high contrast themes. We should decrease the height to 2px or change the box-sizing to border-box since we are adding a border.

The tag of the pull request shouldn't be "chore", chore is used for "changes to the build process or auxiliary tools and libraries such as documentation generation"(http://localhost:3000/docs/contributing/conventions-and-guidelines/#commit-header). Maybe "fix" is appropriate.

[ui5-webcomponents-bot]

🎉 This PR is included in version v2.17.0-rc.2 🎉

The release is available on v2.17.0-rc.2

Your semantic-release bot 📦🚀