Replace outdated dependencies in Blazor Server project template

[mkArtakMSFT]

Blazor Server project template uses openiconic dependency, which is not maintained any more.
This issue tracks the work for choosing a new open-source icons library and moving to it:

aspnetcore/src/ProjectTemplates/Web.ProjectTemplates/content/BlazorServerWeb-CSharp/wwwroot/css/site.css

Line 1 in 274c32e

@import url('open-iconic/font/css/open-iconic-bootstrap.min.css');

Here are some other places, where openiconic dependency exists:

• dotnet/maui: Fixed the openiconic link maui#10749
• dotnet/samples
• dotnet/maui-samples
• dotnet/blazor-samples
• dotnet/aspnetcore.docs

Thanks for contacting us.

We're moving this issue to the .NET 8 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[TanayParikh]

This should be covered via #40935. Not sure if we need a separate top-level issue in planning.