Add translation support for processor config

Problem/Motivation

Thank-you for the awesome module! I have an issue where my ranges are in dollars and depending on whether you are in English or French the dollar signs are place differently.

Steps to reproduce

1. Enable this module on a multilingual site;
2. Add a facet and enable this processor with a mapping 0-5|$0 - $5;
3. Save the facet;
4. Select the translate tab on the facet and add translate;
5. See that the mapping from 2 does not appear as translatable.

Proposed resolution

Adding a schema file that declares the processor configuration as a text data type solves the issue as this config data type is translatable.

Remaining tasks

User interface changes

API changes

Data model changes