Migrated OkHttpJsonApiClient#getMedia and getPictureOfTheDay to MediaClient (#3056)

* With media client APIs migrated to retrofit (#2998)

* With media client APIs migrated to retrofit

* Add test cases and java docs

* Fix test

* Fix build

* Fix build and other minor issues

* Fix tests

* Categories related client API's migrated to retrofit (#3053)

* Commit 1

* searchCategories migrated to retrofit

* SearchCategoriesFragment migrated to new API

* Removed unused code

* Created tests

* implemented searching by prefix
fixed SearchCategoryFragment behaviour where the same categories would be added to the list instead of new ones.

* added tests

* Migrated searchTitles to searchCategories, function behaviour seems identical

* With media client APIs migrated to retrofit (#2998)

* With media client APIs migrated to retrofit

* Add test cases and java docs

* Fix test

* Fix build

* Fix build and other minor issues

* Fix tests

* Categories related client API's migrated to retrofit (#3053)

* Commit 1

* searchCategories migrated to retrofit

* SearchCategoriesFragment migrated to new API

* Removed unused code

* Created tests

* implemented searching by prefix
fixed SearchCategoryFragment behaviour where the same categories would be added to the list instead of new ones.

* added tests

* Migrated searchTitles to searchCategories, function behaviour seems identical

* OkHttpJsonApi#getMediaList migrated to retrofit (#3054)

* Migrated OkHttpJsonApi#getMediaList partially to MediaClient#getCategoryImages

* Migrated rest of OkHttpJsonApi#getMediaList functionality to MediaClient#getCategoryImages

* Removed unused code and tests

* Fixed small bug

* Added tests

* Removed unused CategoryImageController

* getSubCategoryList and getParentCategoryList migrated to retrofit (#3055)

* Migrated getSubCategoryList to retrofit

* Migrated getParentCategoryList to retrofit

* Removed obsolete functions

* Added tests

* Fixed small bugs

* Migrated OkHttpJsonApiClient#getMedia and getPictureOfTheDay to MediaClient

* Removed obsolete functions and added tests

* Fixed merge errors

* With media client APIs migrated to retrofit (#2998)

* With media client APIs migrated to retrofit

* Add test cases and java docs

* Fix test

* Fix build

* Fix build and other minor issues

* Fix tests

* Categories related client API's migrated to retrofit (#3053)

* Commit 1

* searchCategories migrated to retrofit

* SearchCategoriesFragment migrated to new API

* Removed unused code

* Created tests

* implemented searching by prefix
fixed SearchCategoryFragment behaviour where the same categories would be added to the list instead of new ones.

* added tests

* Migrated searchTitles to searchCategories, function behaviour seems identical

* OkHttpJsonApi#getMediaList migrated to retrofit (#3054)

* Migrated OkHttpJsonApi#getMediaList partially to MediaClient#getCategoryImages

* Migrated rest of OkHttpJsonApi#getMediaList functionality to MediaClient#getCategoryImages

* Removed unused code and tests

* Fixed small bug

* Added tests

* Removed unused CategoryImageController

* getSubCategoryList and getParentCategoryList migrated to retrofit (#3055)

* Migrated getSubCategoryList to retrofit

* Migrated getParentCategoryList to retrofit

* Removed obsolete functions

* Added tests

* Fixed small bugs

* Consume login client from data client library (#2894)

Fix actions for review client

Use data client library for notifications

With delete helper migrated to data client

With wikidata edits

With notifications and modifications migrated to data client

With upload migrated to retrofit

Delete unused code

Reuse thank interface from the library

app/src/main/java/fr/free/nrw/commons/Media.java

@@ -29,6 +29,7 @@ import fr.free.nrw.commons.utils.MediaDataExtractorUtil;
 
 public class Media implements Parcelable {
 
+    public static final Media EMPTY = new Media("");
     public static Creator<Media> CREATOR = new Creator<Media>() {
         @Override
         public Media createFromParcel(Parcel parcel) {