set catalog feature flag for integration tests (show)

[mkenigs]

Do some combination of:

• Copy tests in show.bats that are impacted by the catalog and run them with the catalog feature flag set. Make any small changes required to get them passing
• Port those tests to unit tests run with the catalog feature set

In any case:

• Set FLOX_FEATURES_USE_CATALOG=true and _FLOX_USE_CATALOG_MOCK=/dev/null for all other tests in the file
• If anything that isn't minor breaks, skip copied tests and create followup tickets

[mkenigs]

The following need to be copied and made to work with the catalog:

• 'flox show' accepts search output without separator
• 'flox show' - hello
• 'flox show' - hello --all

This one could probably be a unit test, but I'm not sure whether it's worth porting just one test:

• 'flox show' - python310Packages.flask

These are ensuring things get scraped so should be present serverside:

• 'flox show' - python27Full
• 'flox show' - python27Full --all
• 'flox show' - rubyPackages.rails

[mkenigs]

This got merged into the wrong branch