refactor: SPARKED

[kenjis]

Description
The current CLIRequest does not know whether it is Spark request or PHP CLI request.

• add CLIRequest::isSparked()
• spark command uses sparked CLIRequest
• and we will not need the constant SPARKED that makes testing difficult

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• [] User guide updated
• Conforms to style guide

[kenjis]

I thought again, and changed my mind.
I'll take this down for now.