Improve performance/caching of multiple JIRA Issues macros

Page load times tend to increase exponentially when multiple JIRA issues macros are used, even for simple queries.

As a workaround you can limit the amount of issues returned or use dynamic render mode which appears to use caching better, but it could be improved for both modes.

To reproduce:

1. Create a page
2. Add a JIRA issues macro with this XML view: https://jira.atlassian.com/sr/jira.issueviews:searchrequest-xml/temp/SearchRequest.xml?jqlQuery=project+%3D+CONF+AND+issuetype+in+%28Bug%2C+%22New+Feature%22%2C+Improvement%29+AND+fixVersion+%3D+%224.2.2%22+AND+status+in+%28Resolved%2C+Closed%29+ORDER+BY+priority+DESC%2C+key+DESC&tempMax=200
3. Save the page and monitor page load time
4. Edit the page and add copy/paste the JIRA issues macro to create multiples
5. Save the page and monitor page load time

Page will load times will increase exponentially, even if the same query is being returned by each macro.