ES Mapping - Generate JSON

Context:  

The user needs a full JSON to be able to apply it to the mapping, at this stage we are simply providing the file 

To Do :

Generate mapping and download in browser 

AC :

• As a user, I can click on a 'Generate Mapping' option in my Elasticsearch mapping page, which will download a JSON file to my browser
• The file will add the relevant configuration in the order in which they are listed, there will be no merging behaviors 
• The file will be a single JSON block that can be directly appended to the template file on the instance
• If successful, I get an message TBC 
• It will NOT generate if items are in error and display a pop-up

TBC Message success :

" Please note that you will need to append the JSON code block to the Elastic Search mapping file on your instance, and reindex any Elasticsearch indexes, before changes are applied. View documentation here." 

Message JSON error :

"Error: The Elasticsearch mapping file could not be generated due to one or several JSON errors, please resolve these"