Correct autocomplete for values with special characters

This adds a check for any special chars in any value passed to the `DefaultOptions.beforeInsert` callback function. If special chars are found and `skipSpecialCharTest` option is `false`, it will wrap the value in quotation marks.

This fixed autocompleting `~customer+` instead of `~"customer+"`.

![2016-12-03_10.37.11](/uploads/59159623638939933d23b447692775b8/2016-12-03_10.37.11.gif)

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

Closes #25286, #24961

See merge request !7910