Migrate 27 queries under python/ql/src/ from legacy CFG types
(CallNode/AttrNode/NameNode/etc.) to the shared-CFG-based 'Cfg::'
namespace, matching the dataflow API surface introduced earlier on
this branch. ModificationOfParameterWithDefaultCustomizations.qll
is rewritten on top of BarrierGuard, removing the last legacy ESSA
dependency in that file. UnguardedNextInGenerator.ql still uses
ESSA and bridges to the new CFG via Cfg::CallNode.getNode().
Also reformat 14 library and query files that had drifted from
the formatter.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
0a9946121b