Restructure meta-metadata for metric results

Just changed the structure how the metric results are stored into the
meta-metadata records, as I call them. The metric identifier maps to an
associative array containing the score and a report with more details.
This commit closes #23.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add case to display spinning wheel on all rows

If the compute all metrics button is pressed the row for displaying the
spinning wheel could not be found. Hence, I have added a case which
leads to selecting all metric rows.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>