2.14 refactor

[RasonJ]

Updates for the 2.14 plugin:

• will address latest schema changes
• will write events to data prepper
• update UBI header/query_attributes data passing
• polish the js events logged

Depends on https://github.com/o19s/opensearch-ubi/pull/170

[epugh]

Interestingly, while sometimes we get a CORS error and sometimes not, I think the data goes in..

[epugh]

I have one more idea on CORS, so going to try that, and then merge this.