`LocalPath` searched `FullNestedPath()` for the last `!/`, which is just `RealPath` for a file not in
an archive. A host file like `/data/Hello!/world.txt` came back as `/world.txt`, so lookups and
exclusions ran against the wrong path even with nested cataloging off. `ContainerPath` had the same
problem when `FullPath` was set to `RealPath`.
Both now cut `RealPath` off first and only look for a separator in the entry chain after it, which
can't contain `!/` since entry names with it are refused.
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>