Probe remote cache availability on tuist bazel setup

tuist bazel setup now actively probes the resolved remote cache endpoint with the same REAPI GetCapabilities gRPC handshake Bazel performs, including auth, instance name, and TLS handling. If the probe fails (for a TUIST_CACHE_ENDPOINT override, single server endpoint, or any unreachable/advertised endpoint), the setup aborts with a clear error and does not write .bazelrc.tuist, instead of producing config that breaks at the first build.