Cpp: Fix incorrect exception being caught, fix docker warnings (#796)

### Changelog
Cpp: Fix incorrect exception being caught, fix docker warnings #796

### Docs
None

### Description
- Fixes incorrect exception being caught (noticed that in
foxglove/ros-foxglove-bridge@44abb8d)
- Fix docker warnings (`WARN: FromAsCasing: 'as' and 'FROM' keywords'
casing do not match (line 24)`)
- ~Bumps conan recipe version~

cpp/dev.Dockerfile

@@ -21,15 +21,15 @@ ENV CXX=clang++
 
 WORKDIR /src
 
-FROM base as build
+FROM base AS build
 RUN pip --no-cache-dir install conan
 RUN conan profile detect --force
 COPY ./foxglove-websocket /src/foxglove-websocket/
 ARG CPPSTD=17
 ARG ASIO=standalone
 RUN conan create foxglove-websocket -s compiler.cppstd=$CPPSTD --build=missing -o foxglove-websocket*:asio=$ASIO
 
-FROM build as build_examples
+FROM build AS build_examples
 COPY --from=build /root/.conan2 /root/.conan2
 COPY ./examples /src/examples
 RUN conan build examples --output-folder examples/ -s compiler.cppstd=$CPPSTD --build=missing

cpp/foxglove-websocket/include/foxglove/websocket/websocket_server.hpp

@@ -769,10 +769,10 @@ inline void Server<ServerConfiguration>::handleBinaryMessage(ConnHandle hdl, Mes
  length,
  data};
  _handlers.clientMessageHandler(clientMessage, hdl);
- } catch (const ServiceError& e) {
+ } catch (const ClientChannelError& e) {
  sendStatusAndLogMsg(hdl, StatusLevel::Error, e.what());
  } catch (...) {
- sendStatusAndLogMsg(hdl, StatusLevel::Error, "callService: Failed to execute handler");
+ sendStatusAndLogMsg(hdl, StatusLevel::Error, "clientPublish: Failed to execute handler");
  }
  } break;
  case ClientBinaryOpcode::SERVICE_CALL_REQUEST: {