[FEATURE] support multi-root workspace

[zhanba]

如果你的需求与问题相关，请在下面描述一下（Is your feature request related to a problem? Please describe.）

描述你预期的功能表现（Describe the solution you'd like）

• support multi-root workspace
  • add/remove folders
  • open workspace file
  • settings
  • debug
  • ...

描述你考虑过的替代方案（Describe alternatives you've considered）

补充信息（Additional context）