Added proper test for merging of "histogram" aggregate function states

dbms/tests/queries/0_stateless/00919_histogram_merge.reference

@@ -0,0 +1,6 @@
+0	55	101
+55	117	97
+117	199	92
+0	55	101
+55	117	97
+117	199	92

dbms/tests/queries/0_stateless/00919_histogram_merge.sql

@@ -0,0 +1,2 @@
+WITH arrayJoin(finalizeAggregation((SELECT histogramState(3)(number) FROM numbers(10, 190)) + (SELECT histogramState(3)(number) FROM numbers(0, 100)))) AS hist SELECT round(hist.1) AS l, round(hist.2) AS r, round(hist.3) AS cnt;
+WITH arrayJoin(finalizeAggregation((SELECT histogramState(3)(number) FROM numbers(0, 100)) + (SELECT histogramState(3)(number) FROM numbers(10, 190)))) AS hist SELECT round(hist.1) AS l, round(hist.2) AS r, round(hist.3) AS cnt;

dbms/tests/queries/1_stateful/00151_histogram_merge.reference

@@ -1,2 +0,0 @@
-199
-199

dbms/tests/queries/1_stateful/00151_histogram_merge.sql

@@ -1,34 +0,0 @@
-create table test.test_histogram (a Int32) 
-ENGINE = Memory
-
---127.0.0.1
-insert into test.test_histogram (a) SELECT * FROM numbers(10, 190)
-
---127.0.0.2
-insert into test.test_histogram (a) SELECT * FROM numbers(0, 100)
-
-
---make sure upper_bound=199
---when merging AggregationState in both 1,2 and 2,1 order
-
-with
-histogram(3)(a) AS hst,
-arrayJoin(hst) AS hst_array
-select
-round(hst_array.2) AS upper_bound
-from remote('127.0.0.{1,2}', 'test', 'test_histogram')
-having upper_bound = 199
-order by upper_bound desc
-limit 1
-
-with
-histogram(3)(a) AS hst,
-arrayJoin(hst) AS hst_array
-select
-round(hst_array.2) AS upper_bound
-from remote('127.0.0.{2,1}', 'test', 'test_histogram')
-having upper_bound = 199
-order by upper_bound desc
-limit 1
-
-drop table test.test_histogram