[PWGEM] Add configurable to enable/disable side-based TPC drift correction

[Steffimro]

This configurable allows to switch on and off the TPC drift correction to assess the effects of the following PR:AliceO2Group/O2Physics#17846

@romainschotter

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 102 warnings, 🔕 16 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 64dbdee at 2026-09-17 04:44:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 10 errors and 0 warnings.'
Found 10 errors and 0 warnings.
++ [[ 10 -gt 0 ]]
++ cat /sw/BUILD/9bbbd392b3224030a0bf98be6039bae0bfc17aa6/O2Physics-code-check/errors.txt
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:85:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:86:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:87:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:88:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:89:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:90:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:91:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:92:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:93:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGEM/PhotonMeson/TableProducer/photonconversionbuilder.h:94:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
++ [[ 0 -gt 0 ]]
++ [[ 10 -gt 0 ]]
++ exit 1
--

Full log here.