test: move application tests to tests/

test_support/test_helpers -> tests/support; watched_at unified w/ domain test_watched_at (2024-03-15).
Kept inline: users::diary_filter tests (feed_sort_to_direction_all_variants, paged_user_filter_builds_correctly) - pub(super) helpers in private module.
Dropped stale never-compiled users/tests/get_users.rs (old execute signature).

crates/application/tests/users.rs

@@ -0,0 +1,26 @@
+mod support;
+
+#[path = "users/authorize_admin_test.rs"]
+mod authorize_admin_test;
+#[path = "users/get_current_profile_test.rs"]
+mod get_current_profile_test;
+#[path = "users/get_federated_profile_stats_test.rs"]
+mod get_federated_profile_stats_test;
+#[path = "users/get_federated_profile_test.rs"]
+mod get_federated_profile_test;
+#[path = "users/get_local_profile_test.rs"]
+mod get_local_profile_test;
+#[path = "users/get_page_viewer_test.rs"]
+mod get_page_viewer_test;
+#[path = "users/get_profile_settings_test.rs"]
+mod get_profile_settings_test;
+#[path = "users/get_settings_test.rs"]
+mod get_settings_test;
+#[path = "users/resolve_username_to_id_test.rs"]
+mod resolve_username_to_id_test;
+#[path = "users/update_profile_fields_test.rs"]
+mod update_profile_fields_test;
+#[path = "users/update_profile_test.rs"]
+mod update_profile_test;
+#[path = "users/update_settings_test.rs"]
+mod update_settings_test;