Add optional parameter for *showscript to send target to SELF only

[AnnieRuru]

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 will be closed if the above-mentioned criteria are not fulfilled.

Issues addressed

as requested by Kuroe, add optional parameter to allow *showscript to only shown to the player

Changes Proposed

• Add optional parameter for *showscript to send target to SELF only
• also remove the useless script_pushint

Affected Branches

• Master

Known Issues and TODO List

this is copy paste from rathena

[HerculesWSAPI]

This change is 

[AnnieRuru]

how to do the HPM Hook update ?
or have to do it manually ?

[4144]

how to do the HPM Hook update ?
or have to do it manually ?

run make in tools/HPMHookGen