qt-build-utils: do not split include paths by space

Before a string such as "-I /path to Qt/ -I /another/path/" would
be created and then split by space. This works when there are no
spaces in the string but in the example here it becomes
`["-I", "/path", "to", "Qt/", "-I", "/another/path/"]`.

Instead we actually want ["-I", "/path to Qt/", "-I", "/another/path/"]
or we can combine the -I and have ["-I/path to Qt/", "-I/another/path/"].

So instead build a vector of include args to give to Command args
instead of splitting the string. Which then resolves having a space
in your Qt or library path.

Closes KDAB#756

crates/qt-build-utils/src/lib.rs

@@ -618,14 +618,14 @@ impl QtBuild {
 
         let metatypes_json_path = PathBuf::from(&format!("{}.json", output_path.display()));
 
-        let mut include_args = String::new();
+        let mut include_args = vec![];
         // Qt includes
         for include_path in self
             .include_paths()
             .iter()
             .chain(arguments.include_paths.iter())
         {
-            include_args += &format!("-I {} ", include_path.display());
+            include_args.push(format!("-I{}", include_path.display()));
         }
 
         let mut cmd = Command::new(self.moc_executable.as_ref().unwrap());
@@ -634,7 +634,7 @@ impl QtBuild {
             cmd.arg(format!("-Muri={uri}"));
         }
 
-        cmd.args(include_args.trim_end().split(' '));
+        cmd.args(include_args);
         cmd.arg(input_path.to_str().unwrap())
             .arg("-o")
             .arg(output_path.to_str().unwrap())