Add BLSamplePosition table (#272)

New table BLSamplePosition with FK to BLSample, posX, posY, posZ, recordTimeStamp and positionType enum

Author: gfrn

schemas/ispyb/updates/2025_05_01_BLSamplePosition.sql

@@ -0,0 +1,20 @@
+INSERT IGNORE INTO SchemaStatus (scriptName, schemaStatus) VALUES ('2025_05_01_BLSamplePosition.sql', 'ONGOING');
+
+ALTER TABLE Position
+  DROP CONSTRAINT IF EXISTS Position_fk_blSampleId,
+  DROP IF EXISTS positionType,
+  DROP IF EXISTS blSampleId;
+
+CREATE TABLE `BLSamplePosition` (
+  `positionId` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT 'Primary key (auto-incremented)',
+  `blSampleId` int(11) unsigned NOT NULL COMMENT 'FK, references parent sample',
+  `posX` double DEFAULT NULL,
+  `posY` double DEFAULT NULL,
+  `posZ` double DEFAULT NULL,
+  `recordTimeStamp` datetime DEFAULT NULL COMMENT 'Creation or last update date/time',
+  `positionType` enum('dispensing') COMMENT 'Type of marked position (e.g.: dispensing location)',
+  PRIMARY KEY (`positionId`),
+  CONSTRAINT `BLSamplePosition_fk_blSampleId` FOREIGN KEY (`blSampleId`) REFERENCES `BLSample` (`blSampleId`)
+);
+
+UPDATE SchemaStatus SET schemaStatus = 'DONE' WHERE scriptName = '2025_05_01_BLSamplePosition.sql';