use generics in SearchApi

[exaV]

as proposed in #1134

Fixes #1134

[exaV]

It should work but I was unable to get the integration test to work. It fails with (even without my changes)

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.391 s <<< FAILURE! - in org.gitlab4j.api.TestSearchApi
org.gitlab4j.api.TestSearchApi  Time elapsed: 0.391 s  <<< ERROR!
org.gitlab4j.api.GitLabApiException: invalid_grant

[exaV]

Okay I was able to get the tests to work. After my latest change all tests in TestSearchApi are green.

To get it to run I had to remove seedData() method in org.gitlab4j.api.SetupIntegrationTestExtension#beforeAll in my local copy of the code.

[exaV]

@jmini please review

[exaV]

@jmini Please let me know if you need me to change something to get this merged

[jmini]

Yes it is still on my TODO list to review this. Sorry for the delay.

[jmini]

Thank you very much for this contribution 🎉