Find a new namespace for project

As of now [`project`](https://github.com/imagej/imagej-ops/blob/master/src/main/java/net/imagej/ops/transform/project/DefaultProjectParallel.java) currently lives in the transform namespace. However this does not really make sense, seeing as it does not return a `View` like all of the other `transform` `Op`s, and it furthermore does not even wrap any call to `Views`. In reality it is closer to `map` and other global `Op`s.

The question then becomes where `project` then belongs. @ctrueden has suggested creating a new namespace for `Op`s (like `map` and `project`) that perform other `Op`s (maybe `meta` would be a good name, probably another choice would be better). For reference I checked the assignment given to project operations in other projects: itk stores their project operations within [`Filtering/ImageStatistics`](https://github.com/InsightSoftwareConsortium/ITK/tree/master/Modules/Filtering/ImageStatistics/include), however I would not support putting `project` within `FilterNamespace` or `StatsNamespace`. I also checked scikit-image but could not find a project operation.

Start with src/main/java/net/imagej/ops/transform/project/DefaultProjectParallel.java and review how project is organized in the transform namespace. Compare it with map and other global Ops, then examine the namespace alternatives discussed in the issue. Done means reaching agreement on a namespace and relocating project accordingly.

Written by the indexing model from the issue text.