Add *cap_value script command

[Emistry]

Pull Request Prelude

• I have followed proper Hercules code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

• add cap_value(value, min, max) script command.
• its kinda useful in the src if you noticed, so I am sure it could come in handy to add for NPC script usage.

Issues addressed:

• avoid the ugly nested min() and max() combo if needed.

[HerculesWSAPI]

This change is