Add health-dependent color variable

[lokka30]

Add a variable to change color depending on percentage of mob health.

For example:

'41-100': '&a'
'20-40': '&e'
'<20': '&c'

And so we can use like %color% in the nametag?

https://discord.com/channels/752310043214479462/829238692161781770/875679380955869234

[UltimaOath]

Basically identical to the %tiered% and how it functions, except that this new tag will update based on the health and config similar to how health indicator works (edited I noticed I went on a tangent half way into the sentence lol)

[UltimaOath]

Leaving a note here because it's in a similar vein feature wise:
The idea of applying a fake glow effect via PL to entities that are attacked. This glow effect would be colored based based on remaining health of the entity.

[UltimaOath]

nametags:
  tiered-health-placeholder:
    100: '&6'
    50: '&#abc123'
    15: ''
    0: ''

Updated suggestion on implementation. 100/0 are the required top and bottom, and the middle can be any value for different colors. 100 used for all health between it and the next line. So and so forth, until the final X to 0 health is the last color. 0 is considered 'default' otherwise.
Implemented as %tiered-health%

[lokka30]

Being brainstormed in demo actions.yml

[UltimaOath]

settings:
  tiered-health-placeholder:
    100: '&6'
    50: '&#abc123'
    15: ''
    0: ''

Recovering issue for recent player request;
https://discord.com/channels/752310043214479462/760051505067458590/1254269215330930710

Suggested functioning same as:
#278 (comment)