Plugin::build should accept self not &self

[UkoeHB]

What problem does this solve or what need does it fill?

Currently to drill an allocated object into plugins you either need to use a resource or Arc<Mutex<>>. It would nice for the default, most common case to allow consuming plugin content on build..

What solution would you like?

The Plugin trait should only have one method: build(self, &mut App). The existing Plugin trait should be renamed to FullPlugin, and its methods should be &mut not &.

What alternative(s) have you considered?

Continue using resources/Arc<Mutex<>>.

Additional context

IIRC the current &self restriction is from the old plugin design. Don't see any reason or docs saying the plugin methods can't be mutable.

[alice-i-cecile]

Related but distinct things were previously attempted in #4212 and #8101

Yeah I think we should hold this line for now until we have the editor situation sorted out (and maybe also hot code reloading). The wins we get here don't outweigh the cost of trying to put this genie back in the bottle across the ecosystem. Anything that requires "state consumption" can use ECS resources for now.

We can reopen (or likely re-implement) if after we've sorted everything out we decide we can do this.

[BenjaminBrienen]

And #1045