Refactor `saveToLogFile`

[Remi-Gau]

Need to refactor saveToLogFile

src/saveEventsFile.m: metric: exceeded file_length: measured 522 > limit 500
In src/saveEventsFile.m, line 345
| function logFile = saveToLogFile(logFile, cfg)
|                    ^^^^^^^^^^^^^ metric: exceeded cyc: measured 17 > limit 15
MISS_HIT Metric Summary: 53 file(s) analysed, 2 metric deviations(s)
Error: Process completed with exit code 1.

Originally posted by @Remi-Gau in #158 (comment)