logcmdutil: use the same data as {file*} template keywords (issue6642)

Since 0c72eddb4be5 template keywords that show files use a different source of
data than ctx.p1().status(ctx). These two functions in logcmdutil also show
file lists when needed (e.g. log with --debug flag), but previously they used
the old way of just looking at status compared to p1 and it resulted in
differences between e.g. hg log --debug and hg log -T '{file*}'.

test-phases.t needs an adjustment because 7 is a merge commit of two
topological branches and one of them introduces files C, D and E.
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