Add originator mode to the post-condition-mode switch when using the sandbox to make a contract call

[314159265359879]

Is your feature request related to a problem? Please describe.
When I make a contract call using the explorer sandbox, it is tedious to set all the post-conditions, I don't think I can even send additional ones when needed. (when two tokens are send).

Describe the solution you'd like
It would help if we could toggle to "Originator" mode here:
Current options are "Deny mode" (D) or "Allow mode" (A), lets add "Originator mode" (O) in the middle as a third option.

Describe alternatives you've considered
none

[linear]

EXP-286