Adds completion export tests

Introduces tests for well completion exports, validating both unified and split-by-well file formats, enhancing the
reliability of this functionality.

Includes a normalization function to exclude file paths and headers from comparisons, focusing on relevant completion data.

Updates test models with completion export reference files.

.gitignore

@@ -77,6 +77,7 @@ CMakeUserPresets.json
 /Resinsight_Host.creator
 /Resinsight_Host.config
 *.RESINSIGHT_IDX
+*.rspdb
 
 #Python
 *.pyc