Ensure header gets written first time when opening file

[lajohn4747]

resolves #2046
CU-86b0rhymd

Confirmed that for a new log file will have the header only once:

LEVEL,EVENT,TIMESTAMP,SYNTHESIZER CLASS NAME,SYNTHESIZER ID,TOTAL NUMBER OF TABLES,TOTAL NUMBER OF ROWS,TOTAL NUMBER OF COLUMNS
INFO,Instance,2024-06-11 11:47:55.245786,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a36c8ccec65d40fca204ca1afe2baf3d,,,
INFO,Fit,2024-06-11 11:47:55.245925,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a36c8ccec65d40fca204ca1afe2baf3d,1,500,9
INFO,Fit processed data,2024-06-11 11:47:55.344018,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a36c8ccec65d40fca204ca1afe2baf3d,1,500,6
INFO,Sample,2024-06-11 11:47:55.466236,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a36c8ccec65d40fca204ca1afe2baf3d,1,10,9
INFO,Instance,2024-06-11 11:48:04.461437,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a1cc97ff1dc74789a2e24e7754ffdadb,,,
INFO,Fit,2024-06-11 11:48:04.461563,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a1cc97ff1dc74789a2e24e7754ffdadb,1,500,9
INFO,Fit processed data,2024-06-11 11:48:04.558117,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a1cc97ff1dc74789a2e24e7754ffdadb,1,500,6
INFO,Sample,2024-06-11 11:48:04.682670,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_a1cc97ff1dc74789a2e24e7754ffdadb,1,10,9
INFO,Instance,2024-06-11 11:49:21.612837,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_2ce9505e272348fe8ed371b9817813db,,,
INFO,Fit,2024-06-11 11:49:21.613059,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_2ce9505e272348fe8ed371b9817813db,1,500,9
INFO,Fit processed data,2024-06-11 11:49:21.722263,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_2ce9505e272348fe8ed371b9817813db,1,500,6
INFO,Sample,2024-06-11 11:49:21.847287,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_2ce9505e272348fe8ed371b9817813db,1,10,9
INFO,Instance,2024-06-11 11:53:11.433892,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_f831515cfa1e4aa19e2064be948e6749,,,
INFO,Fit,2024-06-11 11:53:11.434110,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_f831515cfa1e4aa19e2064be948e6749,1,500,9
INFO,Fit processed data,2024-06-11 11:53:11.530300,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_f831515cfa1e4aa19e2064be948e6749,1,500,6
INFO,Sample,2024-06-11 11:53:11.652728,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_f831515cfa1e4aa19e2064be948e6749,1,10,9
INFO,Instance,2024-06-11 11:53:44.828702,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_4799f7cd7cd94614b6568bce604cf16d,,,
INFO,Fit,2024-06-11 11:53:44.828923,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_4799f7cd7cd94614b6568bce604cf16d,1,500,9
INFO,Fit processed data,2024-06-11 11:53:44.931025,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_4799f7cd7cd94614b6568bce604cf16d,1,500,6
INFO,Sample,2024-06-11 11:53:45.055451,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_4799f7cd7cd94614b6568bce604cf16d,1,10,9
INFO,Instance,2024-06-11 11:54:09.605423,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_06650191040a43b4a9b7276bae8d812d,,,
INFO,Fit,2024-06-11 11:54:09.605662,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_06650191040a43b4a9b7276bae8d812d,1,500,9
INFO,Fit processed data,2024-06-11 11:54:09.697771,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_06650191040a43b4a9b7276bae8d812d,1,500,6
INFO,Sample,2024-06-11 11:54:09.818474,GaussianCopulaSynthesizer,GaussianCopulaSynthesizer_1.13.2.dev0_06650191040a43b4a9b7276bae8d812d,1,10,9

[sdv-team]

Task linked: CU-86b0rhymd SDV - Add header to log.csv file #2046