Duplicate (or multiples) returned for theme search

[cdils]

I'm seeing duplicate entries in the theme search results for the same slug.

Example

The below screenshot shows a theme search for “ollie”. Left side site is running FAIR Connect 1.2.2 and right side is not running FAIR.

A search for this same term on fair.pm returns duplicate results as well -> https://fair.pm/packages/themes/?keyword=ollie

Steps to Reproduce

Option A: From fair.pm

• Go to https://fair.pm/packages/themes/ and search for any theme (e.g., Ollie)
• Note multiple results for a theme with the same slug

Option B: From a WordPress install

• Log into the admin of a WP site running FAIR Connect v1.2.2 (or later)
• Go to Appearance > Themes
• Search for any theme (e.g., "ollie") and note multiple results

[chuckadams]

As mentioned on Slack, the search code for themes is pretty old and does return duplicates. We should port the query that @jdevalk wrote for plugins.