When listing paths, filter value with a predicate

[ABridoux]

Describe your idea briefly.
The library could offer the possibility to filter listed paths with the paths command based on the value.

Describe the solution you'd like
A predicate could be used to specify how to filter. To throw a relevant error and not crash, the NSPredicate cannot be used. The library could rather use BooleanExpressionEvaluation.

Possible syntax with the -v|--value option.

scout paths -v "value > 10" # keep the number values greater than 10
scout paths -v "value <= 10" # keep the number values lesser than or equal to 10
scout paths -v "10 <= value && value <= 15" # keep the number values between 10 and 15
scout paths -v "value hasPrefix 'hobb'" # keep the values that start with "hobb"
scout paths -v "value matches '[0-9]{3}'" # keep the values composed of exactly 3 digits.

Additional context
The -v|--value option should work coherently with the remaining arguments:

• initial path
• filter on the keys -k|--key option