tooltip fix for hover and code completion on VS code (#9862)

* Update DefaultLSPTagHelperTooltipFactory.cs

- Make the tooltip show the full tagHelperTypeName instead of the reduced name in LSP factory. This method is used in both hover service and code completion service. I also made sure to make only the final tagHelperType name bold.

* Update  DefaultLSPTagHelperTooltipFactoryTest 

- changed three unit tests so we are testing for showing the full name space to reflect the desired behavior

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Tooltip/DefaultLSPTagHelperTooltipFactory.cs

@@ -51,6 +51,14 @@ internal class DefaultLSPTagHelperTooltipFactory(ISnapshotResolver snapshotResol
 
             var tagHelperType = descriptionInfo.TagHelperTypeName;
             var reducedTypeName = ReduceTypeName(tagHelperType);
+
+            // If the reducedTypeName != tagHelperType, then the type is prefixed by a namespace
+            if (reducedTypeName != tagHelperType)
+            {
+                descriptionBuilder.Append(tagHelperType[..^reducedTypeName.Length]);
+            }
+
+            // We make the reducedTypeName bold while leaving the namespace intact
             StartOrEndBold(descriptionBuilder, markupKind);
             descriptionBuilder.Append(reducedTypeName);
             StartOrEndBold(descriptionBuilder, markupKind);

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/DefaultLSPTagHelperTooltipFactoryTest.cs

@@ -92,7 +92,7 @@ World", cleanedSummary);
 
         // Assert
         Assert.True(result);
-        Assert.Equal(@"**SomeTagHelper**
+        Assert.Equal(@"Microsoft.AspNetCore.**SomeTagHelper**
 
 Uses `List<System.String>`s", markdown.Value);
         Assert.Equal(MarkupKind.Markdown, markdown.Kind);
@@ -115,7 +115,7 @@ Uses `List<System.String>`s", markdown.Value);
 
         // Assert
         Assert.True(result, "TryCreateTooltip should have succeeded");
-        Assert.Equal(@"SomeTagHelper
+        Assert.Equal(@"Microsoft.AspNetCore.SomeTagHelper
 
 Uses `List<System.String>`s", markdown.Value);
         Assert.Equal(MarkupKind.PlainText, markdown.Kind);
@@ -166,11 +166,11 @@ Uses `List<System.String>`s", markdown.Value);
 
         // Assert
         Assert.True(result);
-        Assert.Equal(@"**SomeTagHelper**
+        Assert.Equal(@"Microsoft.AspNetCore.**SomeTagHelper**
 
 Uses `List<System.String>`s
 ---
-**OtherTagHelper**
+Microsoft.AspNetCore.**OtherTagHelper**
 
 Also uses `List<System.String>`s", markdown.Value);
         Assert.Equal(MarkupKind.Markdown, markdown.Kind);