Project/Namespace list filter behaves unexpectedly

[vincebrannon]

Setup

• Rancher version: 2.6.11, 2.7.2, 2.7.3
• Rancher UI Extensions: none
• Browser type & version: Chrome Version 114.0.5735.106 (Official Build) (arm64)

Describe the bug
The filter box on "Projects & Namespaces" page can only find namespaces and empty projects.

To Reproduce
Create projects 1 and 2. Create namespace only in project1.

Result
Filter for project, and you will see only project2, the empty one, listed.

Expected Result
Customer would like to be able to filter projects effectively with this, we do know the namespace dropdown menu can also be used to filter.

Screenshots

[richard-cox]

Empty projects are probably shown because we specifically add a 'null' namespace to show projects without namespaces. That process needs to respect the filter.

If the expected result is to be able to use the filter to show both namespaces and projects i think we might just need to tweak the custom projects column definition to include the search field.