Pull in new JSON format

**Describe the refactoring action**
* Pull the code from https://github.com/apache/uima-uimaj-io-jsoncas into the main UIMAJ distribution as `uimaj-io-json`.
* Rename old JSON module to `uimaj-io-json-legacy`

**Expected benefit**
* Make JSON format directly accessible to UIMAJ users without having to draw in an artifact built from another repo (with a different version than UIMAJ).
* One release less to worry about.

Start by comparing the apache/uima-uimaj-io-json repository with the existing JSON module in the UIMAJ distribution. Determine the changes needed to include it as uimaj-io-json and rename the old module to uimaj-io-json-legacy. Done means the new JSON format is available from the main UIMAJ distribution and the module naming is consistent.

Written by the indexing model from the issue text.