Fix IME candidate popup position for BasicTextField2

[m-sasha]

PlatformTextInputSession.platformSpecificTextInputSession now calls DesktopTextInputService.notifyFocusedRect to tell the system where to place the IME candidate window for languages such as Chinese.

Fixes https://youtrack.jetbrains.com/issue/CMP-7467

Testing

• Added testing with BasicTextField2 to WindowTypingLocationTest.
• Tested manually with:

import androidx.compose.foundation.layout.*
import androidx.compose.foundation.text.input.rememberTextFieldState
import androidx.compose.material.*
import androidx.compose.runtime.*
import androidx.compose.ui.*
import androidx.compose.ui.unit.*
import androidx.compose.ui.window.*

fun main() = singleWindowApplication {
    Column(
        Modifier.fillMaxSize().padding(16.dp),
    ) {
        Text("TextField")
        var value by remember { mutableStateOf("") }
        TextField(value = value, onValueChange = { value = it }, modifier = Modifier.width(200.dp))

        Spacer(Modifier.height(64.dp))
        Text("TextField2")
        val state = rememberTextFieldState()
        TextField(state, modifier = Modifier.width(200.dp))
    }
}

This should be tested by QA

Release Notes

Fixes - Desktop

• Fixed the positioning of the IME candidate popup for TextField(TextFieldState) (aka BasicTextField2).

[m-sasha]

Two reviewers due to the addition of PlatformTextInputSession.notifyFocusedRect.

[MatkovIvan]

It's not only desktop change, but I see only Desktop related tests. How does it work for iOS? Web?

[m-sasha]

It should be a desktop-only change. The other platforms don't implement the new method.

[MatkovIvan]

What about web? It seems that they need to implement something like this.

cc @Schahen to check if web should be affected or not
cc @mazunin-v-jb to confirm that iOS doesn't need this functionality in any form

[mazunin-v-jb]

iOS will need that, but for now, iOS doesn't use that method. There's no need to implement it here, I'll do it later myself

[igordmn]

Checked the snippet on Windows - works as well