Editor: support go to implementation (#7890)

Release Notes:

- Added "Go to implementation" support in editor.

crates/lsp/src/lsp.rs

@@ -1136,6 +1136,7 @@ impl LanguageServer {
             document_formatting_provider: Some(OneOf::Left(true)),
             document_range_formatting_provider: Some(OneOf::Left(true)),
             definition_provider: Some(OneOf::Left(true)),
+            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
             type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
             ..Default::default()
         }