Monster hp bar fix

[Jedzkie]

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.

Changes Proposed

In official servers, monster hp bar is not shown when you hit MVP Monsters.

Affected Branches:
master

Issues addressed:

Known Issues and TODO List

[HerculesWSAPI]

This change is 

[AnnieRuru]

can we do this as battle_config ?
or else members will start complaining suddenly seeing a feature they used to and suddenly it disappear

also, MD_BOSS also included mini-bosses like Angeling, Mastering, Chimera, Bloody Knight, etc...
make sure you check

[Jedzkie]

@AnnieRuru sure. Yeah, mini boss also don't have hp bars. even emperiums and barricades

[tlacson7]

how about emperium?

[Jedzkie]

@tlacson7 even emperiums doesn't have hp bar. only normal monsters.

[AnnieRuru]

that's why I also felt like rathena did the wrong way
they use hidemobhpbar mapflag

I think the correct way is just hiding the specific ID of monsters...
can you confirm WoE guardian also has hp bar ?

[4144]

then probably add flag into mob_db to show/hide hp bar?

[Asheraf]

actually we need to be able to set a monster class from the db as in aegis they have 4 classes CLASS_Normal, CLASS_MVP, CLASS_Boss, CLASS_Guardian the hp bar show only for CLASS_Normal also there is a script command to force showing it showmobhp.. this is to be used with other things as well such as the class icon near the name for mobs/pets....