Split out z/OS package data

[pleia2]

In issue #49 a case was made that we have several sources for open source software being developed for IBM z/OS and it now makes sense to split up the repositories for easier maintenance and improved accuracy.

This commit splits out the following:

• Rocket Software into ZOS_Rocket_Software.json

• Everything from github.com/IBM/IBM-Z-zOS/ into IBM_Z_zOS.json

• Everything maintained by the Open Mainframe Project into ZOS_OMP.json

Once this split is completed, we will work on updates to these files.

ZOS_Software_List.json remains as a generic place to put any software that doesn't neatly fit into another category, but I have removed all tools related to the z/OS Open Tools project, since it's very outdated and there's another effort in progress to complete adding these tools into their own source file (see: https://github.com/openmainframeproject/software-discovery-tool/pull/124).

[rachejazz]

Hey @pleia2 I see just one file that is split on this PR. Is the other half not commited onto git?

[pleia2]

Whoops. And I made a mess of rebasing :sweat_smile: but I made it! All four files are here now for review.