rtla/timerlat: Add --stack-format option

rtla/timerlat: Add --stack-format option

In the current implementation, the auto-analysis code for printing the
stack captured in the tracefs buffer of the aa instance stops at the
first encountered address that cannot be resolved into a function
symbol.

This is not always the desired behavior on all platforms; sometimes,
there might be resolvable entries after unresolvable ones, and
sometimes, the user might want to inspect the raw pointers for the
unresolvable entries.

Add a new option, --stack-format, with three values:

- truncate: stop at first unresolvable entry. This is the current
  behavior, and is kept as the default.
- skip: skip unresolvable entries, but do not stop on them.
- full: print all entries, including unresolvable ones.

To make this work, the "size" field of the stack entry is now also read
and used as the maximum number of entries to print, capped at 64, since
that is the fixed length of the "caller" field.

Link: https://lore.kernel.org/r/20260119115222.744150-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>