Bug fixes for Jira REST Java client

[rantoniuk]

Fixes needed for release requested by upstream in #636.

• Set a hardcoded limit of 100 issues to be returned in searchJql() call to fix JiraRestService#getIssuesFromJqlSearch throws an exception #646:

RestClientException{statusCode=Optional.of(400), errorCollections=[ErrorCollection{status=400, errors={}, errorMessages=[The max results parameter has to be between 1 and 5,000.]}]}

• Set explicitly the fields that are needed according to documentation, since passing null doesn't work:

2025-04-22 21:27:52.779+0000 [id=31] WARNING h.plugins.jira.JiraRestService#getIssuesFromJqlSearch: Jira REST client get issue from jql search error. cause: RestClientException{statusCode=Optional.absent(), errorCollections=[]}
org.codehaus.jettison.json.JSONException: JSONObject["fields"] not found.