Logger dont repeat handlers on recall

[fdobad]

On QGIS, when repeatedly calling an fire2a-lib algorithm with verbose, it sets up the logger handlers again, so all logger lines such as 2025-05-26 20:28:17 INFO fire2a.agglomerative_clustering Fin... get's repeated once more every time the algorithm is run from QGIS.

this refactoring of setup_logger avoids this, at the cost of using main as logger name when calling throught cli