[enhancement] filter the "flags" list in each tab to include only flags that are used with the appropriate upload type #3521
Description
Is your feature request related to a problem? Please describe.
The "flags" dropdown/list in the Coverage tab of the Codecov UI shows flags that are only used with test result uploads. Similarly, the dropdown/list in the Tests tab shows flags that are only used with coverage uploads.
Describe the solution you'd like
Each tab's flags list should filter to only show flags that are used with that upload type.