Do not print the internal struct name in LSP tooltip or error message

just strip the `slint::` or `slint::private_api::`
This is not a 100% match to the slint name (eg, LogicalPosition) but
it is better anyway

Author: ogoffart

internal/compiler/langtype.rs

@@ -157,7 +157,12 @@ impl Display for Type {
             Type::Array(t) => write!(f, "[{}]", t),
             Type::Struct(t) => {
                 if let Some(name) = &t.name {
-                    write!(f, "{}", name)
+                    if let Some(separator_pos) = name.rfind("::") {
+                        // write the slint type and not the native type
+                        write!(f, "{}", &name[separator_pos + 2..])
+                    } else {
+                        write!(f, "{}", name)
+                    }
                 } else {
                     write!(f, "{{ ")?;
                     for (k, v) in &t.fields {

internal/compiler/tests/syntax/elements/text.slint

@@ -5,7 +5,7 @@ export component Foo inherits Rectangle {
     Text {
         font-metrics: 42;
 //      ^error{Cannot assign to output property 'font-metrics'}
-//                    ^^error{Cannot convert float to slint::private_api::FontMetrics}        
+//                    ^^error{Cannot convert float to FontMetrics}
 
     }