Migrate imglib2-ops

This branch migrates the `imglib2-ops` component from https://github.com/imglib/imglib into ImageJ OPS, so that it can begin to be refactored into proper `Op` plugins. The idea is that over time, the code in `net.imglib2.ops` can make its way into `net.imagej.ops` until eventually, nothing is left that depends on `net.imglib2.ops` and we can remove the deprecated classes completely.