cli_helper: Ignore errors in the bazel query

[umaucher]

In more complex repositories the bazel query can have errors but still would give the xml output. To still use it ignore the return value of the subprocess and add additional filtering on the output.

[AlexanderLanin]

I don't think we should ignore bazel return codes, as this will ignore every kind of error.

[umaucher]

changed the behaviour to be more expressive and still try to parse as much as possible. IMHO fair enough for a helper? Sample output (used in inc_mw_per):

✔ machine:~/eclipse-score/inc_mw_per
$ bazel run -- //:help
INFO: Analyzed target //:help (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //:cli-help up-to-date:
  bazel-bin/cli-help
  bazel-bin/cli-help.venv.pth
INFO: Elapsed time: 20.912s, Critical Path: 0.01s
INFO: 1 process: 1 action cache hit, 1 internal.
INFO: Build completed successfully, 1 total action
INFO: Running command line: bazel-bin/cli-help
ERROR: ~/.cache/external/score-baselibs+/score/json/internal/parser/vajson/BUILD:16:11: no such package '@@score-baselibs+//ecu/xpad/ara/vector': BUILD file not found in directory 'ecu/xpad/ara/vector' of external repository @@score-baselibs+. Add a BUILD file to a directory to mark it as a package. and referenced by '@@score-baselibs+//score/json/internal/parser/vajson:vajson_parser'
[...]
ERROR: Evaluation of query "deps(//...)" failed: errors were encountered while computing transitive closure
WARNING: --keep_going specified, ignoring errors. Results may be inaccurate
 !! Error in bazel query, help string is incomplete!!:
BAZEL TARGETS:

//:copyright-check   Check for license headers:
                     bazel run //:copyright-check
//:copyright-fix     Fix license headers:
                     bazel run //:copyright-fix
//:docs              Build documentation:
                     bazel run //:docs
//:docs_check        Verify documentation:
                     bazel run //:docs_check
//:help              Output all bazel targets with cli_help tag:
                     bazel run //:help
//:ide_support       Create virtual environment (.venv_docs) for documentation support:
                     bazel run //:ide_support
//:kvs_cpp           Build KVS CPP [build]
//:live_preview      Live preview documentation in the browser:
                     bazel run //:live_preview
✔ machine:~/eclipse-score/inc_mw_per