nmcli: include 'searches' field for nmcli device show

The rpm packaging is failing in tests due to a diff not expecting the new field, as we can see here:

test_003: https://gitlab.freedesktop.org/acabral/diff/-/commit/5d053cbd1539912653240a9c8776c6b1fa9a47e5

test_004: https://gitlab.freedesktop.org/acabral/diff/-/commit/f8faa587d127b81881be7bb00a20314d4b93f7c9

Complete CI log (for fedora:34 failing test, that is failing the above tests): https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/jobs/11609072/raw

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I edited the tests to support the new feature, now it can be reviewed and merged without test conflicts.