[#8] merge folderview from peterbay's repo

[urfdvw]

Changes

This PR uses 'react-local-file system' code from peterbay's fork: https://github.com/peterbay/CircuitPython-online-IDE2, but with following changes

• flexlayout specific object 'config', which is 'activeTabInfo' here, is not used as parameter
  • it is only used for high lighting open file
• Remove file counting
• use default breadcrumb divider (unless some os users are offended)

MISC

• passing making fullpath as part of the enhanced file handle
• fix tab open behaviour
  • if same name same path, open file
  • if same name diff path, give alert

Following up issues

• Code quality: fix file read only in react-local-file
  • remove the dependency as a config file, use parameter
  • make the wording more clear: Binary, readonly, etc.
  • remove runable (not used)
• Code quality: better file structure of the react-local-file system package
• double check tab closing behavior, and open new folder tab behavior.