Update CODEOWNERS file [No hash bump needed]

• Replace David by Volker as central manager
• Add the ci_script folder
• Add the macro folders ans assign to Eoin
• Add the online folder and assign to main creators of online pars
• Add the FSD folder and assign to Radim
• Add Eoin and Ilya as owner of PSD
• Add Martin and Simon as owners or RICH
• Add Mehul as owner of STS