Feature: CEA results reader (summary), especially after batch processing

[ShiZhongming]

CEA results are very granular and can be very intimidating to read.

For example, in the energy demand results .csv file, hundreds of columns are found, while only a few is commonly needed by the users. It could be nice to have an overall .csv file summarising the important columns.

Another example, after batch processing hundreds of scenarios, we are not expecting the users to read through all the outputs folders to get the results. Currently, it is expected from the users to come up with their own script to read through all these scenarios. It could be nice to have the overall .csv file summarising all the scenarios.