perf c2c annotate: Start from the contention line

perf c2c annotate: Start from the contention line

Add support to highlight the contention line in the annotate browser,
use 'TAB'/'UNTAB' to refocus to the contention line.

Signed-off-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Reviewed-by: Jiebin Sun <jiebin.sun@intel.com>
Reviewed-by: Pan Deng <pan.deng@intel.com>
Reviewed-by: Zhiguo Zhou <zhiguo.zhou@intel.com>
Reviewed-by: Wangyang Guo <wangyang.guo@intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>