Feat fetch all

[chengcyber]

Basic Checks

Have you run rush change for this change?

• Yes
• No

If No, please run rush change before, this is necessary.

If adding a new feature, the PR's description includes:

• Reason for adding this feature
• How to use
• A basic example

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

Summary

1. "sparo fetch --all" temporary turn off single branch mode and fetch all remote branches. This makes 'git branch --remote' works
2. "sparo checkout " will automatically run "git remote set-branches --add " once to make "fetch" can fetch those checkout-ed branches.

Detail

How to test it

Local