RPC downtime needs helpful message

[elliotBraem]

During RPC downtime, bos-workspace may give an error like:

✓ bos-workspace running on port 8080!
⋅ [widget/page/projects/Editor.jsx] changed: rebuilding app...
/home/zeeshan/gateway/node_modules/bos-workspace/dist/lib/server.js:168
                    json.result.result = Array.from(new TextEncoder().encode(JSON.stringify(devWidget)));
                                       ^

TypeError: Cannot set properties of undefined (setting 'result')
    at /home/zeeshan/gateway/node_modules/bos-workspace/dist/lib/server.js:168:40
    at Generator.next (<anonymous>)
    at fulfilled (/home/zeeshan/gateway/node_modules/bos-workspace/dist/lib/server.js:5:58)

Node.js v22.2.0
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

This is because we proxy rpc requests and if the original rpc is down, then result will not be set.

TypeError: Cannot set properties of undefined (setting 'result')

We should catch this error and provide a helpful message, like:

log.warn(`Request to default rpc (${default_rpc}) failed and may be facing outages. Try again shortly or configure a different rpc`)

The above implies being able to customize rpc in bos.config.json too, this feature would need to be added.

This also should not impact locally developed widgets