Refactor search engine into own endpoint

[epugh]

Description

Every try contains all of the data about the search engine. This introduces an actual search_endpoint object that you can pick from.

Motivation and Context

Every try drags along a copy of all the search engine end points. We attempt to give them names, like ES 1 or Solr 2 but that's buggy, and not very meaningful to users. Likewise, in a lot of places we show super long urls, like you might see on a cloud hosted version of your search engine, and htose are illegiable. We want to give names to them that are human friendly!

Lastly, in lots of places an Admin type will set up the connection for use by the relevance folks, and maybe we want to introduce some usernames etc? Also give us room to add NEW types of search engines with specific needs.

How Has This Been Tested?

Screenshots or GIFs (if appropriate):

Types of changes

• [] Bug fix (non-breaking change which fixes an issue)
• [] Improvement (non-breaking change which improves existing functionality)
• [] New feature (non-breaking change which adds new functionality)
• [] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [] My code follows the code style of this project.
• [] My change requires a change to the documentation.
• [] I have updated the documentation accordingly.
• [] I have read the CONTRIBUTING document.
• [] I have added tests to cover my changes.
• [] All new and existing tests passed.

[epugh]

• Need to test that we assign a search endpoint to a team when a case is shared with a team in the migration.