[PWGJE] Require MC particles to be properly associated with MC collisions in processQcMultCutCheck

[y-song]

Also added histograms for number of tracks with and without track selections and a histogram for number of particles at the truth level

[github-actions]

O2 linter results: ❌ 32 errors, ⚠️ 38 warnings, 🔕 2 disabled

[alibuild]

Error while checking build/O2Physics/code-check for cd45742 at 2026-08-31 13:34:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 9 errors and 10 warnings.'
Found 9 errors and 10 warnings.
++ [[ 9 -gt 0 ]]
++ cat /sw/BUILD/f1987ae4bc1902bc5710b939322f9073f9ea4738/O2Physics-code-check/errors.txt
PWGJE/Tasks/jetFinderQA.cxx:116:33: error: narrowing conversion from constant 'double' to 'bool' [bugprone-narrowing-conversions,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:117:32: error: narrowing conversion from constant 'double' to 'bool' [bugprone-narrowing-conversions,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:118:33: error: narrowing conversion from constant 'double' to 'bool' [bugprone-narrowing-conversions,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:946:175: error: repeated branch body in conditional chain [bugprone-branch-clone,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:985:15: error: loop variable is copied but only used as const reference; consider making it a const reference [performance-for-range-copy,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:1007:15: error: loop variable is copied but only used as const reference; consider making it a const reference [performance-for-range-copy,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:1299:13: error: Variable 'pt' with floating point type 'double' should not be used as a loop counter [clang-analyzer-security.FloatLoopCounter,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:1305:13: error: Variable 'pt' with floating point type 'double' should not be used as a loop counter [clang-analyzer-security.FloatLoopCounter,-warnings-as-errors]
PWGJE/Tasks/jetFinderQA.cxx:1311:13: error: Variable 'pt' with floating point type 'double' should not be used as a loop counter [clang-analyzer-security.FloatLoopCounter,-warnings-as-errors]
++ [[ 10 -gt 0 ]]
++ cat /sw/BUILD/f1987ae4bc1902bc5710b939322f9073f9ea4738/O2Physics-code-check/warnings.txt
PWGJE/Tasks/jetFinderQA.cxx:45:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead [modernize-deprecated-headers]
PWGJE/Tasks/jetFinderQA.cxx:116:33: warning: implicit conversion 'double' -> 'bool' [readability-implicit-bool-conversion]
PWGJE/Tasks/jetFinderQA.cxx:117:32: warning: implicit conversion 'double' -> 'bool' [readability-implicit-bool-conversion]
PWGJE/Tasks/jetFinderQA.cxx:118:33: warning: implicit conversion 'double' -> 'bool' [readability-implicit-bool-conversion]
PWGJE/Tasks/jetFinderQA.cxx:912:22: warning: statement should be inside braces [readability-braces-around-statements]
PWGJE/Tasks/jetFinderQA.cxx:922:22: warning: statement should be inside braces [readability-braces-around-statements]
PWGJE/Tasks/jetFinderQA.cxx:932:22: warning: statement should be inside braces [readability-braces-around-statements]
PWGJE/Tasks/jetFinderQA.cxx:942:22: warning: statement should be inside braces [readability-braces-around-statements]
PWGJE/Tasks/jetFinderQA.cxx:948:7: warning: do not use 'else' after 'return' [readability-else-after-return]
PWGJE/Tasks/jetFinderQA.cxx:1545:49: warning: redundant boolean literal supplied to boolean operator [readability-simplify-boolean-expr]
++ [[ 9 -gt 0 ]]
++ exit 1
--

Full log here.