[server] Add index for report and run history id columns

[csordasmarton]

Removing a run got slow after we introduced the analysis info table
in the previous 6.16.0. CodeChecker release. Doing some measurement
on the database I tried to run the following query:

begin;
explain (analyze,buffers,timing) delete from runs where id=1;
rollback;

The output looked like this:

 QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------
 Delete on runs  (cost=0.00..1.51 rows=1 width=6) (actual time=0.048..0.050 rows=0 loops=1)
   Buffers: shared hit=3
   ->  Seq Scan on runs  (cost=0.00..1.51 rows=1 width=6) (actual time=0.020..0.024 rows=1 loops=1)
         Filter: (id = 1
         Rows Removed by Filter: 40
         Buffers: shared hit=1
 Planning Time: 0.077 ms
 Trigger for constraint fk_reports_run_id_runs on runs: time=1.728 calls=1
 Trigger for constraint fk_run_histories_run_id_runs on runs: time=0.062 calls=1
 Trigger for constraint fk_bug_path_events_report_id_reports on reports: time=23.935 calls=578
 Trigger for constraint fk_bug_report_points_report_id_reports on reports: time=7.960 calls=578
 Trigger for constraint fk_extended_report_data_report_id_reports on reports: time=6.060 calls=578
 Trigger for constraint fk_report_analysis_info_report_id_reports on reports: time=22042.053 calls=578
 Trigger for constraint fk_analyzer_statistics_run_history_id_run_histories on run_histories: time=0.046 calls=2
 Trigger for constraint fk_run_history_analysis_info_run_history_id_run_histories on run_histories: time=0.033 calls=2
 Execution Time: 22082.691 ms

From this we can see that the bottleneck is the
fk_report_analysis_info_report_id_reports contstraint. Adding indices on
the report_id and run_history_id columns on the join tables (report_analysis_info,
run_history_analysis_info`) solves this problem and reduces the amount of query
time drastically.