Refresh in-memory project cache when there's a cache miss and when a new project is added.

### Steps to recreate

When onbaording a project on to FOSSA, if there a cache miss when searching for a new project the look up returns 0 and the onbaording process proceeds to onbaord a project with an ID of 0. We then get an error saying that there are no maintainers associated with the project (which is true because there is no project with an id of 0)

### Workaround

Delete the maintainer server pod, restarting the pod refreshes the cache with new projects that did not get loaded last time

### Proposed fix

Belt and braces, update the cache when a new project is added to maintaine-d and refresh the cache when there's a miss.