perf check: Introduce 'check' subcommand

Currently the presence of a feature is checked with a combination of
perf version --build-options and greps, such as:

    perf version --build-options | grep " on .* HAVE_FEATURE"

Instead of this, introduce a subcommand "perf check feature", with which
scripts can test for presence of a feature, such as:

    perf check feature HAVE_FEATURE

'perf check feature' command is expected to have exit status of 0 if
feature is built-in, and 1 if it's not built-in or if feature is not known.

Multiple features can also be passed as a comma-separated list, in which
case the exit status will be 1 only if all of the passed features are
built-in. For example, with below command, it will have exit status of 0
only if both libtraceevent and bpf are enabled, else 1 in all other cases

    perf check feature libtraceevent,bpf

The arguments are case-insensitive.
An array 'supported_features' has also been introduced that can be used by
other commands like 'perf version --build-options', so that new features
can be added in one place, with the array

Committer testing:

  $ perf check feature libtraceevent,bpf
           libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
                     bpf: [ on  ]  # HAVE_LIBBPF_SUPPORT
  $ perf check feature libtraceevent
           libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
  $ perf check feature bpf
                     bpf: [ on  ]  # HAVE_LIBBPF_SUPPORT
  $ perf check -q feature bpf && echo "BPF support is present"
  BPF support is present
  $ perf check -q feature Bogus && echo "Bogus support is present"
  $

Reviewed-by: Athira Rajeev <[email protected]>
Signed-off-by: Aditya Gupta <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Disha Goel <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

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