add some feedback to `sandbox secret set`

[josefaidt]

Environment information

System:
  OS: macOS 14.4.1
  CPU: (10) arm64 Apple M1 Pro
  Memory: 555.50 MB / 32.00 GB
  Shell: /opt/homebrew/bin/fish
Binaries:
  Node: 20.12.2 - ~/Library/Caches/fnm_multishells/72748_1715201332327/bin/node
  Yarn: 1.22.19 - ~/Library/Caches/fnm_multishells/72748_1715201332327/bin/yarn
  npm: 10.5.0 - ~/Library/Caches/fnm_multishells/72748_1715201332327/bin/npm
  pnpm: 9.1.0 - ~/Library/Caches/fnm_multishells/72748_1715201332327/bin/pnpm
NPM Packages:
  @aws-amplify/backend: 1.0.0
  @aws-amplify/backend-cli: 1.0.1
  aws-amplify: 6.2.0
  aws-cdk: 2.140.0
  aws-cdk-lib: 2.140.0
  typescript: 5.4.5
AWS environment variables:
  AWS_PROFILE = josef-gen2
  AWS_STS_REGIONAL_ENDPOINTS = regional
  AWS_NODEJS_CONNECTION_REUSE_ENABLED = 1
  AWS_SDK_LOAD_CONFIG = 1
No CDK environment variables

Description

It would be nice if the CLI returned some success message when creating a secret:

> npx amplify sandbox secret set MY_SECRET
Enter secret value: xxx
Successfully created arn:...

[ykethan]

Marking this as feature request.