[db] add support for adding repos on content:// and file:// URIs

This complicates the code for this niche use-case, but is wanted by F-Droid to support communities with bad or no internet connectivity.

libs/database/src/test/java/org/fdroid/repo/RepoAdderTest.kt

@@ -16,6 +16,7 @@ import io.mockk.just
 import io.mockk.mockk
 import io.mockk.mockkStatic
 import io.mockk.slot
+import io.mockk.verify
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
@@ -213,6 +214,10 @@ internal class RepoAdderTest {
             assertTrue(addedState is Added, addedState.toString())
             assertEquals(existingRepo, addedState.repo)
         }
+
+        verify(exactly = 1) {
+            repoDao.updateUserMirrors(42L, listOf(url.trimEnd('/')))
+        }
     }
 
     @Test