Process: Use more rawStd{Out,Err} const methods instead of mutable ones

Avoid using readAllStandard{Output,Error} mutable methods if possible.
Use non-mutable methods when we are not connected to
readyReadStandard{Output,Error} signals.

Change-Id: I2e830e571b9eab2177fd856bbe06dfc5137d9c01
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/webassembly/webassemblyrunconfiguration.cpp

@@ -103,7 +103,7 @@ static WebBrowserEntries emrunBrowsers(Target *target)
         browserLister.start();
 
         if (browserLister.waitForFinished())
-            result.append(parseEmrunOutput(browserLister.readAllRawStandardOutput()));
+            result.append(parseEmrunOutput(browserLister.rawStdOut()));
     }
     return result;
 }