This bug was initially created as a copy of Bug #1799463

I am copying this bug because: 

We should tolerate duplicates in console even if they're not expected.

Description of problem:

Selecting 'all-projects' on the OperatorHub page causes the operator items on the page to be duplicated and breaks the filtering functionality.

Version-Release number of selected component (if applicable):
4.4

How reproducible:
Always under the correct conditions

Steps to Reproduce:
1. Use a 4.4 cluster and ensure the following default sources are available and enabled:
   - redhat-operators
   - certified-operators
   - community-operators
   - redhat-marketplace 
2. Navigate to Operators > OperatorHub
3. Select 'default' from the projects dropdown
4. Note the item count
5. Enter 'test' in the keyword filter
6. Note the filtered item count
7. Select 'all projects' from the projects dropdown
8. Enter 'test' in the keyword filter

Actual results:
Item count is doubled both before and after the filter term is entered and duplicate items are being displayed on the page. Item count also does not match the number of items displayed on the page.

Expected results:
Duplicate items should not be displayed and item count should match the number of items displayed.

Additional info:
Suspect that packageManifest and marketPlacePackageManifest props retreived by firehose component contain overlapping results depending on what catalog sources are available and what namespace is selected. Probably need to either add a special case when all projects is selected, adjust our selectors to ensure no overlap, or add some logic after the call to reduce the package manifest props to a single unique list.