Add json import CLI tool

This tool loads data from json string or file with set of json strings.

Usage for strings:
 bin/data-load -t (or --table) <table_name> -s (or --string) <json_string>
or
 echo <string> | bin/data-load -t (or --table) <table_name>

Usage for files:
 bin/data-load -t (or --table) <table_name> -f (or --file) <file_path>
or
 cat <file_path> | bin/data-load -t (or --table) <table_name>

For help:
 bin/data-load -h (or --help)

Change-Id: I5bb799e9d0ad2896325c04b881995588b738636e
Implements: blueprint bulk-data-load
Merge "Add json import CLI tool"