fix(kernel-time): correct total/kernel time calculation in JSON output

[Benncs]

Problem

kp_kernel_timer miscalculated total time, kernel count, and total kernel time in JSON output. Problem was not present in kp_reader_json'and 'kp_reader implementation.

Fix

Reused kp_reader_json's logic and unified code in kp_shared.

Impact

• JSON outputs correct values
• Explicitly linked kp_reader_json to kp_shared

[masterleinad]

Can you provide the output before and after this pull request?

[Benncs]

With the develop branch on my program with the following environment variable
export KOKKOS_TOOLS_TIMER_JSON="1"

Before:

{
"kokkos-kernel-data" : {
    "total-app-time"         :      1.319,
    "total-kernel-times"     :      2.217,
    "total-non-kernel-times" :     -0.898,
    "percent-in-kernels"     : 168.09,
    "unique-kernel-calls"    :                     56,
    "region-perf-info"       : [
       {
           "kernel-name"    : "ParticlesContainer::__allocate_buffer__",
           "call-count"     : 26,
           "total-time"     : 0.000058,
           "time-per-call"  :       0.00000224,
           "kernel-type"    : "PARALLEL-SCAN"
       },
....
}

After:

{
  "total-app-time" : 1.31087,
  "total-kernel-time" : 0.598734,
  "total-non-kernel-time" : 0.71214,
  "percent-in-kernels" : 45.6744,
  "unique-kernel-calls" : 36,
  "region-data" : [
    {
      "region-name": "cycleProcess",
      "call-count": 10,001,
      "total-time": 0.70493,
      "time-per-call": 7.04859e-05,
      "kernel-type": "REGION"
    }
,...
    }