* order sources by library count when migrating (closes#4703)
* Use plain menu instead of full-on sheet
(cherry picked from commit ba8abd94a8bcbe409e96cf7d606852a789e439ed)
# Conflicts:
# app/src/main/java/eu/kanade/tachiyomi/ui/browse/migration/sources/MigrationSourcesController.kt
# app/src/main/java/eu/kanade/tachiyomi/ui/browse/migration/sources/MigrationSourcesPresenter.kt