general: new CFG_SCOAP3_SITE flag
- Introduces new CFG_SCOAP3_SITE flag to introduce SCOAP3 specific modifications in core modules.
- If CFG_SCOAP3_SITE=1 renames collections accordingly to journals or publishers.
Signed-off-by: Samuele Kaplun <samuele.kaplun@cern.ch>