[Improvement] Add var-length arguments in job template

### What would you like to be improved?

Current job template argument only supports fixed-length arguments. For example, if the argument list is `--foo bar --foo1 bar1` and if `--foo1` doesn't have a value, we can only use an empty string for `--foo1`, which is inconvenient.

It would be better that we can support var-length arguments, so users can support `-foo bar` and `-foo bar --foo1 bar1`.

### How should we improve?

_No response_