[jQuery topics] Standardize code block language identifiers for accurate syntax highlighting

[Zneeky]

Description:

Some documentation examples are missing the appropriate language identifier on fenced code blocks, which results in inaccurate or missing syntax highlighting.

For example, this Razor section is currently declared without a language:
In `using-infragistics-loader.mdx"

**In Razor:**

```
<script src="http://localhost/igniteui/js/infragistics.loader.js"></script>

$(Html.Infragistics()
    .Loader()
    .ScriptPath("http://localhost/igniteui/js/")
    .CssPath("http://localhost/igniteui/css/")
    .Render()
)
```

Expected

It should use the correct language identifier (csharp), similar to other Razor examples:

**In Razor:**

```csharp
@using Infragistics.Web.Mvc;

<link type="text/css" href="@Url.Content("~/css/themes/infragistics/infragistics.theme.css")" rel="stylesheet" />
<link type="text/css" href="@Url.Content("~/css/structure/infragistics.css")" rel="stylesheet" />
```