fix(files): Ensure renaming state is correctly reset

fix(files): Ensure renaming state is correctly reset

Problem: Is a node is renamed and the new name is out of the current
visible list of nodes the component will be recycled, this means
the props will change, so when the `onRename` functions is about to reset
the state the `this.source` will point to a different node.

To fix this, but also to separate business logic from visual representation,
the logic is moved into the renaming store and the component is only
responsible for rendering.

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>