Add number_of_items to arguments of test_tender_data_open_eu

Also minor cosmetic changes

@@ -357,7 +357,7 @@ def test_tender_data_openua(intervals, number_of_items, number_of_lots, meat):
     return data
 
 
-def test_tender_data_openeu(intervals, number_of_lots, meat):
+def test_tender_data_openeu(intervals, number_of_items, number_of_lots, meat):
     accelerator = intervals['accelerator']
     # Since `accelerator` field is not really a list containing timings
     # for a period called `acceleratorPeriod`, let's remove it :)

@@ -7,9 +7,9 @@ Suite Teardown  Test Suite Teardown
 ${mode}         belowThreshold
 @{used_roles}   tender_owner  provider  provider1  viewer
 
-${number_of_items} ${1}
-${number_of_lots}  ${1}
-${meat}            ${1}
+${number_of_items}  ${1}
+${number_of_lots}   ${1}
+${meat}             ${1}
 
 *** Test Cases ***
 Можливість оголосити однопредметний тендер