Cache report counts when Dynamic Severity is enabled

[mattmundell]

What:

Add caching of report counts for users who have Dynamic Severity enabled.

Why:

Improves the speed of GET_REPORTS when Dynamic Severity is enabled.

Most noticeable on GSA Reports page, because other pages only need to count single reports (which is usually fast even without the cache).

This also prepares for switching to Dynamic Severity only.

How did you test it:

1. with user1, switch to dynamic severity
2. delete from report_counts;
3. with user1, go to GSA > Reports
4. select * from report_counts; <= should return rows
5. with user2, go to GSA > Reports
6. select report_counts.user, count(*) from report_counts group by report_counts.user; <= should return 2 rows
7. with user1, switch off dynamic severity
8. 6 should show 1 row
9. with user1 got to GSA > Reports
10. with user1, switch on dynamic severity
11. 6 should show 1 row
12. with user1 go to GSA > Reports
13. 6 should show 2 rows
14. do a --rebuild
15. 6 should show 1 row

Checklist:

• Tests
• CHANGELOG Entry