Create a common feature branch for the track 2 management work.

[JimSuplizio]

It would be less turbulent for master to do the work to update the new resource manager libraries to track 2 on a feature branch. This is where the lion's share of the work should be done. It should also take periodic merges (at least weekly) from master.

@mitchdenny was has already created feature/mgmt-engsys-convergence, setup a skeleton ci.yml and aggregate pom (as part of this PR and merged into the feature branch).

There's also a pending PR with the following changes:

1. Moves all the mgmt folders into sdk/resourcemanager & renames them to match module name.
2. Pulls azure-resourcemanager into sdk/resourcemanager folder.
3. Moves intermediate parent POM into sdk/resourcemanager folder (I know this will get deleted eventually, its just an intermediate step).
4. Changes all versions from 2.0.0-SNAPSHOT to 2.0.0-beta.1 to match our convention for pre-release libraries.
5. Adds placeholder CHANGELOG.md files
6. Adds the resource manager modules to the resource manager aggregate pom and adds this aggregate pom to the root aggregate pom which is necessary to hook everything up for the build pipeline.
7. Adds the resourcemanager Artifacts to ci.yml which is effectively telling the pipeline what it needs to build

We should get this PR merged in sooner rather than later.