[7.0] Invalidate Mavenizer caches when using `--refresh-dependencies`

[Jonathing]

This is trivially easy to do, since we can check the state of that using StartParameter#isRefreshDependencies(). In project, this is: project.getGradle().getStartParameter().isRefreshDependencies(). So, it just has to be implemented on the Mavenizer side. I would prefer to have some sort of caching invalidation to trigger on Mavenizer's part, instead of just having ForgeGradle delete the caches folder for that specific Forge version from the Mavenizer working directory (located in ~/.gradle/caches/minecraftforge/forgegradle/mavenizer).