[lldb/crashlog] Skip non-crashed threads in batch mode

When using the `crashlog` command in batch mode, most users only care
about the crashed thread and end up having to scroll past all the
non-crashed threads, which is not a good user experience.

Now that `-c|--crashed-only` is set by default, we should also apply
that behavior for batch mode: Only the crashed thread and "Application
Specific Backtrace" threads will be shown to the user in batch mode.

The user will still have the ability to show all the threads if they use
`--no-crashed-only` which will parse the symbols from the report, or
with `-a|--load-all-images` which will fetch binaries and debug info
from the build record and symbolicate every thread.

rdar://106329893

Differential Revision: https://reviews.llvm.org/D157852



Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>