Fix batch fit page so that dropdown links to results of batch fitting

[butler]

The dropdown list in the fit page brings up the selected data file plot useful in setting up the batch but after the batch has run the fit page cannot access the results of the batch — hence all manipulation of results must be done on batch fit page.

However the unsuspecting user, seeing the new plot window pop up with a fit (which is just the theory curve based on the model parameters on the page) can wrongly assume the "model" line is the fit result.

A ticket was generated to put a warning on the fit page. However, it would be nice to also restructure "view fits" on the batch page to be more obviously seperate from plotting of data columns AND provide better instructions. For example - could move to the top and/or put box around it.

Even Longer term one would like to get the results back to the batchpage so could pop up stuff properly.

[butler]

This may be addressed by the updates from Lewis O'driscoll? moving to 4.1 so we don't forget to close it.