Send search request as POST for large queries

[zgoda-mobica]

Is your feature request related to a problem? Please describe.
Jira API allows search requests to be performed either as GET or POST, with POST suggested for queries that can't be encoded as query params. I have a query with ~60k clauses, ~60 bytes each after encoding as query param.

Describe the solution you'd like
For queries that can't be encoded as query params use POST request with JSON payload instead of GET.

[ssbarnea]

I totally agree with your proposal. Now you only need to make a PR to address it.

[hdost]

There's even a PR currently pending that requires some changes #548

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[zgoda]

For over a year I used only POST requests for search in Jira and did not notice any issues. I think this should be default - it's hard to know what's the url size boundary and in theory this depends on servlet container implementation (can't say as I use only Tomcat).