ALICE 3: Add empty skeleton for the TRK digitization

[mconcas]

@atriolo

[github-actions]

REQUEST FOR PRODUCTION RELEASES:
To request your PR to be included in production software, please add the corresponding labels called "async-" to your PR. Add the labels directly (if you have the permissions) or add a comment of the form (note that labels are separated by a ",")

+async-label <label1>, <label2>, !<label3> ...

This will add <label1> and <label2> and removes <label3>.

The following labels are available
async-2023-pbpb-apass4
async-2023-pp-apass4
async-2024-pp-apass1
async-2022-pp-apass7
async-2024-pp-cpass0
async-2024-PbPb-apass1
async-2024-ppRef-apass1

[alibuild]

Error while checking build/O2/fullCI_slc9 for 3471252 at 2025-02-15 10:17:

## sw/BUILD/o2checkcode-latest/log
--
========== List of errors found ==========
++ GRERR=0
++ grep -v clang-diagnostic-error error-log.txt
++ grep ' error:'
++ GRERR=1
++ [[ 1 == 0 ]]
++ mkdir -p /sw/INSTALLROOT/abfe7f70fbf0a4d1bbf866cf73da5bb813c42c97/slc9_x86-64/o2checkcode/1.0-local84/etc/modulefiles
++ cat
--

Full log here.