perf scripts python: Add initial script file with usage information

Added necessary modules, including the Perf-Trace-Util
library, and defines the required functions and variables
for using perf script python. The perf_trace_context and
Core modules for tracing and processing events has been
also imported. Added usage information.
Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/f2f1a62f1cc69f44a5414da46a26a4cf124d2744.1689961706.git.anupnewsmail@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/gecko.py

+# firefox-gecko-converter.py - Convert perf record output to Firefox's gecko profile format
+# SPDX-License-Identifier: GPL-2.0
+#
+# The script converts perf.data to Gecko Profile Format,
+# which can be read by https://profiler.firefox.com/.
+#
+# Usage:
+#
+#     perf record -a -g -F 99 sleep 60
+#     perf script report gecko > output.json
+
+import os
+import sys
+from typing import Dict
+
+# Add the Perf-Trace-Util library to the Python path
+sys.path.append(os.environ['PERF_EXEC_PATH'] + \
+	'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
+
+from perf_trace_context import *
+from Core import *
+
+# Uses perf script python interface to parse each
+# event and store the data in the thread builder.
+def process_event(param_dict: Dict) -> None:
+	pass
+
+# Trace_end runs at the end and will be used to aggregate
+# the data into the final json object and print it out to stdout.
+def trace_end() -> None:
+	pass