collecting_institutions must follow `lab_code_1`

[Aberdur]

The current implementation of institutions in relecov-platform does not align with the new requirement that institutions must be determined based on the field lab_code_1.

• Add in the ddbb table a new column lab_code_1 in the `core.samples table
• Populate already loaded samples using the laboratory_adress.json
• Update queries to use lab_code_1 instead of collecting_institution