Advanced string parsing

[ABridoux]

Describe your idea briefly.
Offer another string parsing for string in Swift.

Describe the solution you'd like
Currently, string parsing is done in ScoutCLT which has some limitations because of Bash/Zsh syntax. Scout could offer another parsing library when scripting is not possible. This could be especially useful for graphic applications.

Additional context
For instance, commands like sum, average can be achieved with scripting, but could also be available directly within scout.

For instance

sum(Robert.scores)

could be interpreted as follow:

explorer.get("Robert", "scores", .slice(.first, .last)).sum // Int?