ASAN wasn't able to keep track of `boost::coroutine` context switches, and would lead to many false positives being detected. By switching to `boost::coroutine2` and `ucontext`, ASAN is able to know about the context switches advertised by the `boost::fiber` class, which in turn leads to more cleaner ASAN analysis.
The `HTTPClient` class initializes a global SSL context via `initializeSSLContext()`. However, it had no way to release it, which caused memory leaks flagged by the LeakSanitizer. Multiple LSAN suppressions in the sanitizers' suppressions file were masking these leaks. Our test code also manually called `initializeSSLContext()` in each test without guaranteed cleanup on failure paths.
This change fixes these memory leaks by adding a `cleanupSSLContext()` method to properly release the global SSL context, and removes the corresponding LSAN suppressions. The change further refactors the `HTTPClient` tests to use a Google Test fixture (`HTTPClientTest`) that manages the SSL context lifecycle via RAII (SetUp/TearDown), making it impossible for tests to leak the context.
This change adds support for sanitizer build options in CI builds workflow. Currently `asan+ubsan` is enabled, while `tsan+ubsan` is left disabled as more changes are required.
