Demos: Minor Improvements to Sample Pages

[brauerj-gc]

Description

Minor Improvements to three sample pages:

Demos/Blazorise.Demo/Pages/Tests/DataGrid/GroupSinglePage.razor - Had no sort selected though the description suggested it should be gender Demos/Blazorise.Demo/Pages/Tests/ListViewPage.razor - Added more samples Demos/Blazorise.Demo/Pages/Tests/SelectListPage.razor - Added more samples

How Has This Been Tested?

Local browser

Types of changes

• [x] Bug fix for sample
• [x] New Samples

Checklist:

• [x] The PR is submitted to the correct branch (master for dev, rel-1.x for maintenance).
• [x] My code follows the code style of this project.
• [n/a] I've added relevant tests.