Mousetrap is used as the help-tool to listen to keystrokes

Added currentDiffIndex getter to store that holds
the index of currently active diff file in the list

Instead of computing it on the component, we will take advantage of it
being available for all components in DiffsApp

Testing keyboard navigation and jumpToFile()

- replaced file.too_large
- replaced file.text
- replaced file.collapsed

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/53304

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/54807

Improve the renderign of new and existing discussions
by reducing the number of watchers on each object & array.
Previously every discussion change would trigger an update for every
discussion component.

Also tidied up some components to get them closer to our docs.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51506

This caused many pain points when working with it.
Part of the data was camel cased the other snake case.
Other parts where snake case & then getting converted in components,
this conversion has the potential for leaking memory.

This changes that & makes it consistent with what it returned from the
API, snake case.

This restores the behaviour of showing the expand all button on diffs
even when only a single file is collapsed.
Previously the button would only show when all files are collapsed.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51737

This re-implements image commenting in merge request diffs.
This feature was previously lost when the merge request
page was refactored into Vue.

With this, we create an overlay component. The overlay
component handles displaying the comment badges
and the comment form badge.
Badges are displayed based on the position attribute
sent with the discussion.

Comment forms for diff files are controlled through
a different state property. This is so we don't
tie comment forms to diff files directly creating
deep nested state. Instead we create a flat array
which holds the file hash & the X & Y position of
the comment form.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/48956

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

This reverts commit 740ae2d1, reversing
changes made to 1ba47de5.

This reverts commit 2411ecb5, reversing
changes made to 58a0df7e.

Discussions were being toggled by jquery DOM querying them and toggling
visibility but in vue, only the open discussions will be in the DOM
Fix includes:
 - Adds a getter to the store to get the expanded discussions
 - Adds an action to collapse a discussion
 - When the user clicks the button, all data needed is now accessible
   through a getter and we can dispatch an action to toggle the discussion
   within the state, instead of showing/hiding with jQuery
 - Removes hardcoded properties

Resolves #48237

Exports state to allow tests
Adds specs for the getters that didn't have any.