Add new col BLSession.icatId for the internal ICAT visit ID

Author: KarlLevik

schemas/ispyb/updates/2025_05_28_BLSession_icatId.sql

@@ -0,0 +1,6 @@
+INSERT IGNORE INTO SchemaStatus (scriptName, schemaStatus) VALUES ('2025_05_28_BLSession_icatId.sql', 'ONGOING');
+
+ALTER TABLE BLSession
+  ADD icatId int(11) unsigned COMMENT 'The internal ICAT ID for this BLSession';
+
+UPDATE SchemaStatus SET schemaStatus = 'DONE' WHERE scriptName = '2025_05_28_BLSession_icatId.sql';