Support Messages PlaceholderAPI

[flavioope]

Is your feature request related to a problem? Please describe.
I'm always frustrated when not being able to use placeholders api in messages.
This is just a suggestion.

Describe the solution you'd like
Well, I would like support for placeholderapi to be added to all messages since this would be very useful for those of us who configure our servers to do some things.

I would like if in the future it is possible to add this please and thank you

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.