[FG7] Add a way to configure Tools (Mavenizer/Slimelauncher)

[RealMangorage]

This is mainly a PR to discuss the most ideal way of handling the configurability of these tools that FG7 uses.

The build script would look like this, to override a tool.

dependencies {
    mavenizer "net.minecraftforge:minecraft-mavenizer:0.3.3"
    slimelauncher "net.minecraftforge:slime-launcher:0.1.0"

    implementation(minecraft.dep("net.minecraftforge:forge:1.21.5-55.0.23"))
}