[webui] do not crash on incomplete patchinfo during release request creation
[api] ensure that there will no double entries for product repos
[api] fix indexing of product repositories
[ci] do not crash on single execution of product tests
[api] use "name" instead of "product" inside of product element
[backend] allow a register flavor for SLE 12 again

Just "module" and "extension" is known atm.
[api] some basic fixes for released binary search