[ADD] selfconsumption: Implement automatic field population in report

I am adding a new feature to the 'selfconsumption' module that automates the population of the following fields in the report:

Page 1:
- CAE [in the project tab]

Page 2:
- SIGNATURE DATE [today's date]

Page 3-4-...:
- NAME AND SURNAME OF HOLDERS (PSA from the "in process" or "active" table)
- HOLDERS' ID (PSA from the "in process" or "active" table)
- CUPS (PSA from the "in process" or "active" table)

This feature enhances efficiency when generating reports by automatically filling in these fields. It also simplifies the report generation process for users.