Add Expand All Feature

[RedHeadphone]

The current version of react-json-grid doesn't provide an expand-all feature, which can be very useful when dealing with nested grids. Users have to manually expand each nested grid, which can become time-consuming and tedious. This issue proposes adding an expand-all prop to the JSONGrid Component that allows users to expand all nested grids with ease, enhancing the user experience and improving usability.

[RedHeadphone]

Better approach I think is a props defaultExpandDepth which takes integer value (default value: 0 and min value: 0), which makes all nested grid with depth <= defaultExpandDepth expanded by default

[RedHeadphone]

Possible new feature:
A prop that accepts key-tree (tree like structure object with all keys that needs to be expanded) and expands all grid according to the key-tree. This can be useful if someone wants to keep selective nested grid open by default.