build: protobuf dependency fixes, libusb build

- docker protobuf dependencies, cross-compilation
- device/trezor protobuf build fixes, try_compile
- libusb built under all platforms, used by trezor for direct connect

cmake/test-protobuf.proto

@@ -0,0 +1,7 @@
+syntax = "proto2";
+
+import "google/protobuf/descriptor.proto";
+
+message Success {
+    optional string message = 1;
+}