Update StatisticsSenderService to not use reserved key name in the JSON document

[makortel]

See cms-sw/cmssw#41975

• master Changed 'type' to 'read_type' to avoid keyword class in UDP message cmssw#42060
• 13_1_X Changed 'type' to 'read_type' to avoid keyword class in UDP message [13_1] cmssw#42098
• 13_0_X Changed 'type' to 'read_type' to avoid keyword class in UDP message [13_0] cmssw#42099
• 12_6_X Changed 'type' to 'read_type' to avoid keyword class in UDP message [12_6] cmssw#42100
• 12_5_X Changed 'type' to 'read_type' to avoid keyword class in UDP message [12_5] cmssw#42101
• 12_4_X Changed 'type' to 'read_type' to avoid keyword class in UDP message [12_4] cmssw#42102
• 10_6_X Changed 'type' to 'read_type' to avoid keyword class in UDP message [10_6] cmssw#42103