SOAExtensions/ZipUtils.h - Use explicit 32bit type, for clarity, and default initialise

added all-slots label

• [2020-07-11 00:05] Validation started with lhcb-lcg-dev3#1325
• [2020-07-11 00:06] Validation started with lhcb-sanitizers#621
• [2020-07-11 00:07] Validation started with lhcb-gaussino#761
• [2020-07-11 00:08] Validation started with lhcb-lcg-dev4#1339
• [2020-07-11 00:08] Validation started with lhcb-gauss-dev#2445
• [2020-07-11 00:09] Validation started with lhcb-head#2648
• [2020-07-11 00:10] Validation started with lhcb-dd4hep#584
• [2020-07-11 00:10] Validation started with lhcb-test-efficiency#126
• [2020-07-11 00:10] Validation started with lhcb-gaudi-head-py3#412
• [2020-07-11 00:11] Validation started with lhcb-new-cmake#128
• [2020-07-11 00:15] Validation started with lhcb-gaudi-head#2661
• [2020-07-11 08:48] Validation started with lhcb-lcg-dev4#1340
• [2020-07-11 15:51] Validation started with lhcb-new-cmake#129
• [2020-07-12 00:05] Validation started with lhcb-new-cmake#130
• [2020-07-12 00:06] Validation started with lhcb-lcg-dev3#1326
• [2020-07-12 00:07] Validation started with lhcb-dd4hep#585
• [2020-07-12 00:09] Validation started with lhcb-sanitizers#622
• [2020-07-12 00:09] Validation started with lhcb-test-efficiency#127
• [2020-07-12 00:09] Validation started with lhcb-head#2649
• [2020-07-12 00:09] Validation started with lhcb-lcg-dev4#1341
• [2020-07-12 00:10] Validation started with lhcb-gauss-dev#2446
• [2020-07-12 00:10] Validation started with lhcb-gaudi-head-py3#413
• [2020-07-12 00:10] Validation started with lhcb-gaudi-head#2662
• [2020-07-12 00:29] Validation started with lhcb-coverity#515

merged

mentioned in commit 90ea89c1

added Event model modernisation labels