Run the Bitwarden SDK's live end-to-end tests against Vaultwarden (#7953)

* Add a test seeder behind the unsafe_test_mode feature

For the end-to-end tests: with the feature, /test/seeder answers the calls the
SDK's live tests make to a seeder API (POST /seed with SingleUserScene or
TestVectorUserScene, DELETE /seed/<playId>), behind HTTP basic auth from
TEST_SEEDER_USERNAME and TEST_SEEDER_PASSWORD, and 404 without them.

It creates accounts without any checks, so no release build has the feature.
CI builds and tests it with sqlite.

* Run the SDK live tests against the test seeder

tools/sdk-live-tests/run.sh builds the server with unsafe_test_mode and runs
the live tests of the SDK's e2e/wasm suite. For SDK versions whose tests log in
to one given account, each user test vector with a master password is seeded
with its vault on a fresh server; for versions that seed their own accounts,
the tests get the seeder's address. Every vector runs, then a summary.

The workflow runs it by hand, and on changes to the seeder or the runner.

* Run the SDK live tests daily

* Test the published SDK package by default in the SDK live tests

src/api/mod.rs

@@ -4,8 +4,13 @@ mod icons;
 mod identity;
 mod notifications;
 mod push;
+#[cfg(feature = "unsafe_test_mode")]
+mod test_seeder;
 mod web;
 
+#[cfg(feature = "unsafe_test_mode")]
+pub use test_seeder::routes as test_seeder_routes;
+
 use rocket::serde::json::Json;
 use serde_json::Value;