Show ContributorsTab only if you have permission to (#402)

add isRepoAdmin

extend Adapters

add check to RepoDetails

refactor var names

reformat code

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: M M Arif <mmarif@swatian.com>
Reviewed-on: https://gitea.com/gitnex/GitNex/pulls/402
Reviewed-by: M M Arif <mmarif@swatian.com>

app/src/main/res/layout/list_repos.xml

@@ -83,6 +83,14 @@
                 android:textSize="16sp"
                 android:visibility="gone" />
 
+            <CheckBox
+                android:id="@+id/repoIsAdmin"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:buttonTint="#FFFFFF"
+                android:checked="false"
+                android:visibility="gone" />
+
             <LinearLayout
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"