Support for decoding stacktraces in log views

[broonie]

When the vmlinux for a kernel built with debug information is available then it is possible to translate the addresses printed in backtraces:

<4>[ 62.189031] do_el0_svc_compat+0x24/0x48

into references to the file and line number the relevant code was generated from:

<4>[ 62.189031] do_el0_svc_compat (arch/arm64/kernel/syscall.c:159)

It would be helpful if the log display in the dashboard had the ability to do that, this will require that we actually build and store the vmlinux, I filed a separate ticket for that kernelci/kernelci-project#509 - since decoding the logs can be a bit slow we perhaps want to consider only doing that on demand, possibly even UI triggered.