Previously, the `showStagedIcon` property was doing the opposite
of what its name suggested. It was rendering the staged icon when
`showStagedIcon` was `false` and rendering the regular icon when
it was `true`.
**Why?**
Previously it managed this as an internal data property, but there
was extra complexity involved because the component doesn't have
all the information it needs (i.e. the `mouseOver` prop).
This is a good opportunity to colocate the data prop with the component
that has the information to change it (i.e. `file_row`) and let
`new_dropdown/index` receive this value as a prop.
This file tree displays all the diff files in a tree like format
Each file is taken and converted into a tree with folders
Each folder can be toggled open & closed
Clicking a file will scroll to the diff file & highlight with a glow affect
Searching the tree list will search only files & return a list of the
files without any folders
Each file row contains an icon to show changed, new file or deleted
Each row will also contain the added & removed lines count
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/14249
