* Added topics validation, fixed repo topics duplication (#4031)

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Added tests

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Fixed fmt

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Added comments to exported functions

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Deleted RemoveDuplicateTopics function

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Fixed messages

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Added migration

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* fmt migration file

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* fixed lint

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Added Copyright

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Added query solution for duplicates

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Fixed migration query

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Changed RegExp. Fixed migration

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* fmt migration file

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Fixed test for changed regexp

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Removed validation log messages

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Renamed migration file

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* Renamed validate function

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

* add topic models and unit tests

* fix comments

* fix comment

* add the UI to show or add topics for a repo

* show topics on repositories list

* fix test

* don't show manage topics link when no permission

* use green basic as topic label

* fix topic label color

* remove trace content

* remove debug function