Utils: Rename PathChooser::{f,setF}ileName() to {f,setF}ilePath()

It's returning a FilePath, so it's a better fit.

Keep the old versions as inline function now to ease downstream migration.

Change-Id: I535887928018f42b92895c8b0c82527f0d55e5ca
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/nim/project/nimtoolchainfactory.cpp

@@ -111,7 +111,7 @@ void NimToolChainConfigWidget::applyImpl()
     Q_ASSERT(tc);
     if (tc->isAutoDetected())
         return;
-    tc->setCompilerCommand(m_compilerCommand->fileName());
+    tc->setCompilerCommand(m_compilerCommand->filePath());
 }
 
 void NimToolChainConfigWidget::discardImpl()