Auto format repo code

[Naton1]

The code here has clearly been worked on by numerous people over several years, and the current code formatting shows that (it's a bit inconsistent in many places).

It'd be nice if the code formatting here was enforced via some formatter like spotless so that it's easier to read, and cleaner. Personally I like palantir's java format.

I'm happy to make this change but wanted to bring it up first before doing it.

This is really easy to do with gradle, like:

plugins {
    ... existing plugins
    id("com.diffplug.spotless") version "6.25.0"
}

...

spotless {
    java {
        palantirJavaFormat()
    }
}

// optional, to format on every build:
tasks.named("spotlessCheck") {
    dependsOn("spotlessApply")
}