Make JSONP versus GET an option for Solr, default to JSONP

[epugh]

Description

New functionality to allow you to specific GET instead of JSONP for the apiMethod to Solr. If you have a API that is mimicking Solr, well, you don't need the JSONP if you hvae proper cors support. THis can simplify some folks lives

Motivation and Context

Baby step towards supporting the Solr V2 API (which is JSON POST), and introduces into the wizard a option to have settings for a serach engine.

In the future maybe we share a search engine with a Team, so thers can pick from a list...

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.