Remove prev/next buttons on issues and merge requests
## What does this MR do?
Remove prev/next buttons on issues and merge requests sidebar
## Are there points in the code the reviewer needs to double check?
No
## Why was this MR needed?
The buttons were rarely used and added at least 1 query each on every page load which we could live without.
## What are the relevant issue numbers?
#18026
## Screenshots (if relevant)
Below is how it looks. Not sure if it's too much empty space. #17697 discusses a possible substitute for what to put there.


See merge request !4442
Notes are awardables
## What does this MR do?
Makes sure we can :thunder_cloud_rain: comments/notes.
## What are the relevant issue numbers?
Follows up upon !2901, depends on !3785Closes#3655
## Screenshots (if relevant)
TODO
See merge request !4291
Upgraded jQuery to version 2
## What does this MR do?
Upgrades jQuery to 2.2.1.
Had to include the task_list JS file directly as it includes jQuery 1 directly https://github.com/github-archive/task_list/blob/master/app/assets/javascripts/task_list.coffee#L8 so when we change jQuery to `jquery2` it was including both jQuery 1 & 2.
## Are there points in the code the reviewer needs to double check?
For any JS errors
## What are the relevant issue numbers?
Closes#12440
See merge request !4384
- Move the `TwoFactorAuthsController`'s `new` action to `show`, since
the page is not used to create a single "two factor auth" anymore. We
can have a single 2FA authenticator app, along with any number of U2F
devices, in any combination, so the page will be accessed after the
first "two factor auth" is created.
- Add the `u2f` javascript library, which provides an API to the
browser's U2F implementation.
- Add tests for the JS components
Clicking search pill focuses field
When clicking the pill in the search field, it now focus the field. Previously you would have to make sure you click in the field.
Fixed an issue where clicking out of the field wouldn't remove the focus
outline
Also reduced some of the HTML to remove what isn't needed
See merge request !4279