Search exact phrase

• Elasticsearch-only
• ~"EE Starter"
• Search for an exact phrase in an exact order.
• Capitalization and punctuation is ignored.
• Applies to all search fields in GitLab, including issue search bar, merge request search bar, and top right search bar on all pages.
• Use double quotes as the syntax, i.e. "Hello terrible world"
• Same as what is described here: https://www.google.com/intl/en_u/insidesearch/tipstricks/all.html.