Support ALTER ROUTINE LOAD JOB stmt, for example:
```
alter routine load db1.label1
properties
(
"desired_concurrent_number"="3",
"max_batch_interval" = "5",
"max_batch_rows" = "300000",
"max_batch_size" = "209715200",
"strict_mode" = "false",
"timezone" = "+08:00"
)
```
Details can be found in `alter-routine-load.md`
This CL mainly changes:
1. Reorganized the code logic to limit the supported json format to two, and the import behavior is more consistent.
2. Modified the statistical behavior of the number of error rows when loading in json format, so that the error rows can be counted correctly.
3. See `load-json-format.md` to get details of loading json format.