Add more repo search tests and /api/repo/search integration tests

[Morlinest]

Add some more tests. Also fixes #2446.

Two integration tests will not pass with current implementation of repo search api because it doesn't return all repositories accessible to user if he is not logged or is different from logged user

[lunny]

CI failed.

[Morlinest]

@lunny I told you it will and why.

I've added 8 new repositories to tests, 4 (2x public, 2x private) are owned by user15, 2 (1x public, 1x private) owned by user16 and user15 is collaborator in both of them and 2 repositories (1x public, 1x private) owned by organization which is owned by user15. That means if you search for public repositories accessible (and related) to user15, you should get 4 public repositories (2 owned by user15, 1 owned by user16 and 1 owned by organization he owns).

You should get only public (directly owned or accessible + related by any other non-private rules) repositories of user if it is anonymous search or logged user is different to that user. Am I thinking right?

[Morlinest]

@lunny @lafriks I think, this should return 2, not 3 (only directly owned repositories). Organization repositories should be included with collaborate flag. What do you think? Same applies to line 112. Or add something like organization flag.

[lunny]

Orgnization repositories should be in collaborate, I think it's right.

[Morlinest]

Fixed tests and added 2 new tests for pages and pagesize limit

[Morlinest]

Tests failed as expected with current implementation of api and repo search function. I've done tests with #2371 and it will pass these new tests (#2371 rebased on this PR can be found in test-repo-search-implementation).

[Morlinest]

Merged to #2371.