Stats_Summary in TO API uses non-RFC3339 date/time strings

[jagan-parthiban]

Parent Issue: #5911

Breaking down the parent issue #5911 in smaller issues to raise separate, reviewable PRs for each of the services.

Traffic Control components affected:

• Traffic Ops
• Documentation

Current behavior:

Stats_Summary Using Deprecated TimeNoMod & TimeLayout

curl --request GET \
  --url https://localhost:8443/api/4.1/stats_summary


{
	"response": [
		{
			"statDate": "2023-03-09",
			"summaryTime": "2023-03-09 00:59:12+05",
			"cdnName": "cdn101",
			"deliveryServiceName": "all",
			"statName": "daily_maxgbps",
			"statValue": 101
		}
	]
}

Expected behavior:

Stats_Summary to Use RFC3339 Format

curl --request GET \
  --url https://localhost:8443/api/5.0/stats_summary


{
	"response": [
		{
			"statDate": "2023-03-09",
			"summaryTime": "2023-03-09T00:59:12+05:30",
			"cdnName": "cdn101",
			"deliveryServiceName": "all",
			"statName": "daily_maxgbps",
			"statValue": 101
		}
	]
}

Steps to reproduce:

Make the above api call to 4.1 version