Fix failing build due to deprecated boost::filesystem functions

[boxanm]

Description

Summary:

Addresses https://github.com/norlab-ulaval/libpointmatcher/issues/574

Changes and type of changes (quick overview):

• Replaced deprecated boost::filesystem::complete with boost::filesystem::absolute
• Replaced deprecated boost::filesystem::extension(path) with path.extension().string()
• Added a check if a filename contains an extension

[sonarcloud[bot]]

Quality Gate failed

Failed conditions
C Maintainability Rating on New Code (required ≥ A)

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