RegisterFileType doesn't work properly when user had made a previous choice

Example

```
touch file.idf
```

Right click file.idf, open With > "Notepad.exe" and tick "Always use this app to open .idf files"

This will populate a registry entry here at `HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.idf\UserChoice`

```
C:\Windows\system32> reg.exe QUERY HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.idf\UserChoice
ProgId REG_SZ Applications\notepad.exe
Hash REG_SZ s3i1KTucehE=
```

Create an installer with a QS script that does this

```
var targetDir = installer.value("TargetDir").replace(/\//g, '
');
console.log("RegisterFileType: targetDir=" + targetDir);

component.addElevatedOperation("RegisterFileType", "idf", `${targetDir}
EP-Launch.exe %1`, "EnergyPlus Input Data File", "text/plain");
```

The filetype association is not overriden by the installer since the UserChoice one above takes precedence (and is not overwritten). The actual reg entries are created around here: https://github.com/qtproject/installer-framework/blob/0ec58b6586f688c7d46c707c3eedfcc807387c3f/src/libs/installer/registerfiletypeoperation.cpp#L107-L121

I think the UserChoice needs to be deleted or overwritten in `RegisterFileTypeOperation::performOperation`