Enable project sharing

The current plan is to enable pipeline servers per project. Organizations need to be enable multiple users to share & contribute to the same pipelines. For example, a pipeline might include steps with Python scripts/notebooks from multiple users or different personas (data scientist, ops user) might track & manage the same pipeline. Currently, there is no way to enable project sharing. Because of the pipelines consideration, we need to enable project sharing to allow users to share a pipeline server. 

Scope of this story:

1. Enable project sharing at the user level.
2. Enable project sharing at the group (OpenShift groups) level.
3. Provide 2 levels of sharing access:
   1. Admin - full edit & delete access to all aspects of the project and the ability to view & edit permissions, i.e. sharing 
   2. Edit - full edit access to all aspects of the project, but no ability to view or edit permissions
4. Users that have access to a project via sharing should be able to view & edit shared projects from the projects list. 
5. For model serving, the list of deployed models is based on projects access. This needs to continue to function in the same way with project sharing. Example: if I have access to project 1 via sharing, I should see deployed models for project 1 in the model serving list from the left nav menu. 

Mocks: https://www.sketch.com/s/b073af35-46b7-46f0-afe0-5db079848ad9