Fix clang-format version and eventually upgrade from v15 to v17

[valassi]

I am using two different machines

[avalassi@itgold91 gcc11/usr] ~> clang-format --version
clang-format version 17.0.6 (AlmaLinux OS Foundation 17.0.6-5.el9)
[avalassi@itgold91 gcc11/usr] ~> more /etc/redhat-release 
AlmaLinux release 9.4 (Shamrock Pampas Cat)

[avalassi@itscrd90 bash] ~> clang-format --version
clang-format version 15.0.7 (Red Hat 15.0.7-2.el9)
[avalassi@itscrd90 bash] ~> more /etc/redhat-release 
AlmaLinux release 9.2 (Turquoise Kodkod)

All code so far was formatted with the latter ie clang-format v15.

I noticed some differences between clang-format 15 and 17.
The templates for codegen etc must be ported to v17.

For the moment I will simply fix the version to <=15 using clang-format from cvmfs.