Visual error indicator when gRPC server reflection fails

[nbgraham]

This was called out in #5518 as future work

Reproduction steps:

1. Create a new gRPC request
2. Enter a URL where nothing is hosted, like localhost:9999
3. Click the server reflection button

Actual:
No visual response on the screen.

Expected:
Some indication of the error.

Logs

[2023-07-25 11:37:26.659] [error] Error occurred in handler for 'grpc.loadMethodsFromReflection': Error: 14 UNAVAILABLE: No connection established
    at callErrorFromStatus (/Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/@grpc/grpc-js/build/src/call.js:31:19)
    at Object.onReceiveStatus (/Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/@grpc/grpc-js/build/src/client.js:410:73)
    at Object.onReceiveStatus (/Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/@grpc/grpc-js/build/src/client-interceptors.js:323:181)
    at /Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/@grpc/grpc-js/build/src/resolving-call.js:93:78
    at process.processTicksAndRejections (node:internal/process/task_queues:77:11)
for call at
    at ServiceClientImpl.makeBidiStreamRequest (/Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/@grpc/grpc-js/build/src/client.js:394:34)
    at ServiceClientImpl.serverReflectionInfo (/Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/@grpc/grpc-js/build/src/make-client.js:105:19)
    at /Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/grpc-reflection-js/build/src/client.js:59:46
    at new Promise (<anonymous>)
    at Client.listServices (/Applications/Insomnia.app/Contents/Resources/app.asar/node_modules/grpc-reflection-js/build/src/client.js:40:16)
    at getMethodsFromReflection (/Applications/Insomnia.app/Contents/Resources/app.asar/main.min.js:40605:36)
    at loadMethodsFromReflection (/Applications/Insomnia.app/Contents/Resources/app.asar/main.min.js:40629:25)
    at /Applications/Insomnia.app/Contents/Resources/app.asar/main.min.js:40566:87
    at node:electron/js2c/browser_init:2:97846
    at EventEmitter.<anonymous> (node:electron/js2c/browser_init:2:81359)