Add API endpoint for accessing repo topics (#7963)

* Create API endpoints for repo topics.

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Generate swagger

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Add documentation to functions

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Grammar fix

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix function comment

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Can't use FindTopics when looking for a single repo topic, as it doesnt use exact match

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Add PUT ​/repos​/{owner}​/{repo}​/topics and remove GET ​/repos​/{owner}​/{repo}​/topics

* Ignore if topic is sent twice in same request, refactoring.

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix topic dropdown with api changes.

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Style fix

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Update API documentation

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Better way to handle duplicate topics in slice

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Make response element TopicName an array of strings, instead of using an array of TopicName

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Add test cases for API Repo Topics.

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix format of tests

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix comments

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix unit tests after adding some more topics to the test fixture.

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Update models/topic.go

Limit multiple if else if ...

Co-Authored-By: Antoine GIRARD <sapk@users.noreply.github.com>

* Engine as first parameter in function

Co-Authored-By: Antoine GIRARD <sapk@users.noreply.github.com>

* Replace magic numbers with http status code constants.

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix variable scope

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Test one read with login and one with token

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Add some more tests

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Apply suggestions from code review

Use empty struct for efficiency

Co-Authored-By: Lauris BH <lauris@nix.lv>

* Add test case to check access for user with write access

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Fix access, repo admin required to change topics

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Correct first test to be without token

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

* Any repo reader should be able to access topics.

* No need for string pointer

Signed-off-by: David Svantesson <davidsvantesson@gmail.com>

routers/api/v1/swagger/repo.go

@@ -246,3 +246,17 @@ type swaggerFileDeleteResponse struct {
 	//in: body
 	Body api.FileDeleteResponse `json:"body"`
 }
+
+// TopicListResponse
+// swagger:response TopicListResponse
+type swaggerTopicListResponse struct {
+	//in: body
+	Body []api.TopicResponse `json:"body"`
+}
+
+// TopicNames
+// swagger:response TopicNames
+type swaggerTopicNames struct {
+	//in: body
+	Body api.TopicName `json:"body"`
+}