Improve the Lagrangian drag models

Summary

• Remove the redundant CdRe function in PlessisMasliyah
• Improve header file documentation
• Modernise the code style

Resolved bugs

N/A

Risks

• No changes in output
• No changes to user input

Tests

• Compilation (incl. submodules):
  • linux64ClangDPInt32Opt (clang11)
  • linux64GccDPInt32Opt
  • linux64GccSPDPInt64Debug
• Alltest: No error