[PWGCF] Added histograms for efficiency as a function of eta pt and centrality

[nidamalikk]

No description provided.

[github-actions]

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

[alibuild]

Error while checking build/O2Physics/code-check for 89e0f9f at 2026-07-03 14:17:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 2 errors and 10 warnings.'
Found 2 errors and 10 warnings.
++ [[ 2 -gt 0 ]]
++ cat /sw/BUILD/da6906e92d44ffa5e1cb62164991f0ae4c50b854/O2Physics-code-check/errors.txt
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:450:23: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:451:23: error: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast,-warnings-as-errors]
++ [[ 10 -gt 0 ]]
++ cat /sw/BUILD/da6906e92d44ffa5e1cb62164991f0ae4c50b854/O2Physics-code-check/warnings.txt
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1291:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1293:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1295:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1297:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1299:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1301:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1303:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1305:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1307:32: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/EbyEFluctuations/Tasks/netchargeFluctuations.cxx:1309:32: warning: statement should be inside braces [readability-braces-around-statements]
++ [[ 2 -gt 0 ]]
++ exit 1
--

Full log here.

[nidamalikk]

@lauraser Dear Laura, can you please merge it into master as well?