Clear roots before rebuilding navigation dictionary (#18766)

* Clear roots before rebuilding navigation dictionary.

* Added tests to verify fix.

* Correct test implementation.

* Convert integration tests with method overloads into test cases.

* Integration test compatibility supressions.

Author: AndyButland

tests/Umbraco.Tests.Integration/CompatibilitySuppressions.xml

@@ -127,13 +127,6 @@
     <Right>lib/net9.0/Umbraco.Tests.Integration.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Services.EntityServiceTests.CreateTestData</Target>
-    <Left>lib/net9.0/Umbraco.Tests.Integration.dll</Left>
-    <Right>lib/net9.0/Umbraco.Tests.Integration.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Services.TemplateServiceTests.Deleting_Master_Template_Also_Deletes_Children</Target>